samouraiwallet

[samouraiwallet]

Wallet Update 0.99.85 - ‘Get in Cahoots’

In March we introduced Cahoots within an experimental section of the wallet. Cahoots is a suite of tools to create and handle collaborative peer-to-peer CoinJoin transactions between two wallets. Unlike our Whirlpool CoinJoin service, Cahoots transactions do not require a blinded coordinator server to function. A bare bones implementation of PayJoin known as Stowaway and an enhanced STONEWALL that we named STONEWALLx2 were added to the wallet for advanced users to help test the bleeding edge of privacy enhancing transactions.

We are very excited to release these privacy features to the wider public as of version 0.99.85. We have created what we hope is an intuitive and friendly interface for performing an inherently complex task. As usual, these features are a work in progress and your feedback will help refine the usability as development progresses. With that all out of the way, let us dive right in.

You can get the latest update from Google Play as of today.

apk hash sha-256 of version 0.99.85 : 1746c78c407f61c7794e4096dc014978d22f309796b9a5268c0e54d5d7ca5751

Toggle Cahoots before sending

You invoke Cahoots from the Send screen of your wallet. You will be asked to choose between two types of Collaborative transaction.

STONEWALLx2

This transaction makes use of a collaborators UTXO set in addition to your own to compose the transaction. The result is a high entropy “mini CoinJoin” transaction. STONEWALLx2 is a great way to quickly mix on demand when sending to any third party by enlisting the help of a privacy conscious friend. In this transaction, both the sender and the collaborator split the miner fee down the middle.

Bob wants to send to Charlie, so he gets Alice to STONEWALLx2 with him.

Stowaway

Stowaway is designed to blend in and look like a typical bitcoin transaction. Outside observers will not be able to tell that the Stowaway transaction is a two person CoinJoin. Additionally the true amount sent is not revealed on the blockchain. Unlike STONEWALLx2, Stowaway transactions can only be sent to the same person you are collaborating with. This makes Stowaway a great option for mixing when paying your privacy conscious friend. In this transaction the sender pays the full transaction fee.

Bob wants to send to Alice, so they do a Stowaway together. 

Thank you

As always we appreciate your continued support of the project.

We are available as always to answer any questions on support.samourai.io or by email at support@samouraiwallet.com

You can download Samourai Wallet from the Google Play Store

Stop by our active telegram channel of over 1,200 privacy activists and say hello.

[samouraiwallet]

A holistic approach to CoinJoin

Earlier this week I was asked the differences between Wasabi and Whirlpool by a user in our Whirlpool telegram channel. Of course, both implementations are based on ZeroLink, and both implementations generally do the same thing. I believe I gave a fair comparison between the two tools. My original comments can be found here.

As I mentioned in my original comments, all CoinJoin transactions are affected by merging inputs if proper precautions are not taken by the wallet software. You have to think of "mixing" in a holistic way, it isn't a single process that affords bulletproof privacy. Certainly anyone claiming they have solved privacy concerns in Bitcoin is a liar.

As we see it, there are two main aspects of "mixing", the actual CoinJoining of UTXOs between participants, which both Samourai and Wasabi provide implementations of, and secondly the actual spending of those UTXOs by the user in a way that doesn't compromise their privacy, what we like to call PostMix Strategy, which only Samourai provides currently.

In the CoinJoin protocol itself there are some key differences in the quality of the mixes that each implementation creates. For example: In Samourai Whirlpool, each mix is "theoretically perfect" - What this means in practice is each mix has the maximum amount of entropy possible for a transaction of that composition - For a 5 input / 5 output Whirlpool transaction this means there are 1496 possible interpretations and no possible deterministic links between any of the inputs and outputs (See: KYCP.org Example ) . Additionally as we do not have a concept of "unmixed change" within the mix you do not see the distinct "peeling chain" pattern on the blockchain. Instead you see more of a fractal tree branch cloud emerge. (See: OXT Whirlpool Explorer )

Alternatively in Wasabi's implementation of ZeroLink there is routinely 30-60% of inputs issued from the same previous transaction, visually identifiable deterministic links between inputs and outputs, and multiple outputs belonging to a single participant in a given transaction, essentially mixing with yourself. These factors in combination with the fact unmixed change is part of the actual transaction as well as the static address used to collect the coordinator fee would disqualify these are transactions as “Theoretically Perfect”.

When viewed in isolation these differences are not serious issues. The peeling chain and unmixed change can be mitigated against by the user staying around until their entire amount has been mixed for example, but when viewed holistically and crucially with lack of a PostMix spending strategy these architectural differences have serious consequences when common user behavior intervenes.

This was demonstrated by the trivial de-anonymization of Wasabi's own donation to The Tor Project which carelessly merged an input in a transaction with a 100% deterministic links (See: KYCP) that revealed not only a Wirex account address, but also 38 fully mixed inputs as their own (See: KYCP)

My point is not to kick a competitor when they are down, my point is, if this can happen to the experts who run Wasabi then this is absolutely happening on a broader scale with less sophisticated users, and they likely have no idea it is happening, let alone what steps they need to make to prevent it.

How to prevent these issues

A well thought out PostMix strategy in combination with a well defined CoinJoin protocol is essential and must work in conjunction with each other.

We disagree strongly with the approach taken by Wasabi in response to these raised concerns - which seem to be well intended but utterly naive - that users should read long Medium articles and learn the finer details of proper Coin Control techniques before spending.

This is a dangerous burden to put on users and an arrogant position to take by the developers. Samourai has instead developed multiple PostMix spending tools that by default will apply advanced coin selection rules to help make sure that the transactions you make after mixing are not leaking unwanted meta data on the block chain as you spend and guaranteeing healthy amounts of entropy as a cloak of plausible deniability.

We have spent years developing and fine tuning our coin selection algorithms, testing them against tools we have developed and Open Sourced to score the transactions. We have invited Wasabi to use these tools to help strengthen their postmix spending proposition (See: 1 2) which was unfortunately rebuffed.

We have innovated on Peer2Peer CoinJoin transactions between you and a friend designed to mix as you spend. And we have implemented PayJoin which is a type of transaction that appears to be a normal "simple" transaction with 2 outputs, but is in fact another Mini CoinJoin where even the amount displayed on the blockchain is misleading. This type of transaction is especially subversive as it successfully tricks analysis platforms to incorrectly cluster the inputs - creating a cloud of false positives.

I knew that it was likely that Wasabi would respond negatively to these comments, but I would suggest to fix the underlying issues that are putting users are risk instead of choosing to Doxx or launch personal attacks against Samourai or our staff.

[samouraiwallet]

Introducing 0.99.81 - Enter The Dojo

This is an exciting one, so strap in. We are happy to announce 0.99.81 which brings in many Quality of Life updates, some bug fixes, and the highlight feature of pairing to your own self hosted Dojo node.

You can get the latest update from Google Play as of today.

apk hash sha-256 of version 0.99.81 : 073fa50552c07449538bc402519a237eb72f02ecf102bf8a415287a5dda05932

Dojo Pairing

Early last month we Open Sourced our back end infrastructure allowing you to self host your own Dojo full node. Today, as of version 0.99.81 we have introduced the ability to pair a newly created Samourai Wallet directly to your Dojo full node over Tor, bypassing our servers entirely. This allows you to be entirely sovereign and independent of Samourai operated servers. 

Pairing is a simple process. Navigate to your fully synced Dojo maintenance control panel with the Pairing QR code visible. In your Samourai Wallet tap “Pair to existing Dojo”  and then scan the QR code. Once paired you will be invited to create a new wallet.

It is important to keep in mind that the full Dojo pairing process will include routines for restoring existing wallets, but this update is specifically for pairing newly created wallets. Restoring your existing wallet with Dojo is currently unsupported in this version.

Default Bech32 Addresses

Samourai Wallet was among the first to deliver full bech32 support to users in May 2018 , directly contributing to a reduction in the miner fees that Samourai Wallet users pay when transacting. In the 0.99.81 update we are happy to announce that bech32 addresses are now the default address type used by the wallet. If you are looking for other address types they are still available from the advanced toggle on the receive screen.

Improved QR scanner

Lets face it, at Samourai we love QR codes. From simple receive addresses, to Z85 encoded packet streams that ultimately get broadcast to space, we rely on QR codes as a way to efficently transmit data in a peer-2-peer manner. We’re happy to roll out an updated QR scanner that is more responsive when dealing with the denser QR codes that are being created. This doesn’t sound like a big deal, but you’ll notice the difference when you use it.

Tor updates

We have continued to work hard on refining the built in Tor layer of Samourai Wallet, with most users able to achieve stable performance with decent speed. By the very nature of Tor, it will never be as fast as Clearnet, but with continued investment in refining our implementation and contributing improvements and code to the upstream maintainer we hope to increase the stability of our Tor implementation. Along with stability improvements all Tor connections are now via v3 .onion addresses. This includes connections to your own Dojo and our own servers. Finally, you are also now able to manually invoke a new Tor identity. This can be achieved from the status bar notification or from the Network Dashboard in your wallet.

STONEWALL Updates

This one is a little technical, but the long and short of it is we have strenghend STONEWALL even further with slight tweaks to the coin selection and transaction composition rules.

We have made some changes to our STONEWALL algorithm to optimize against deanonymization attacks. Previous iterations allowed for the miner fee of a STONEWALL to be paid entirely from one of the two UTXO sets, as of this version, STONEWALL miner fees are equally split between the two sets.

This change also applies for STONEWALLx2. From 0.99.81 onward both you and your collaborator will split the miner fee equally, so in effect your collaborator is paying a very small sum to mix with you.

Thank you

As always we appreciate your continued support of the project.

We are available as always to answer any questions on support.samourai.io or by email at support@samouraiwallet.com

You can download Samourai Wallet from the Google Play Store

Stop by our active telegram channel of over 1,000 privacy activists and say hello.

[samouraiwallet]

Introducing Samourai Dojo 1.0 - Open Source and available to install today

We are proud to announce the release and open sourcing of Samourai Dojo. Dojo is professional back end software infrastructure that sits on top of and augments a Bitcoin Core full node to power the most private bitcoin wallet on the market, Samourai Wallet. This is a huge milestone for us as we have been working towards this moment since we started Samourai in 2015; a huge win for the sovereignty of individual users; a win for bitcoin privacy; and a win for Open Source software.

TL;DR – Up until now you have needed to trust Samourai servers with knowledge of your bitcoin public keys, but now you can now run and host your own Dojo server and bypass us entirely. This is the most private way of using Samourai Wallet.

The GitHub Repository: https://github.com/Samourai-Wallet/samourai-dojo/

Who is it for?

Samourai Dojo is for anyone who wishes to use Samourai Wallet in the most private way possible. Using default Samourai Wallet gives you access to the most advanced transactional privacy enhancing technologies available in any wallet on the market with features such as STONEWALL, STONEWALLx2, Stowaway, and soon Whirlpool, but the trade off is that you must trust Samourai servers with knowledge your public keys. 

Practically this means that even though third party observers and blockchain analysis snoops won’t be as effective when trying to track you versus users of other wallets, the operators of Samourai Wallet theoretically can. By running your own instance of Samourai Dojo and connecting it to your Samourai Wallet you are getting the same transactional privacy tools without leaking any information to our servers.

What is it?

Samourai Dojo has been battle tested, powering all current Samourai Wallet clients. This is professional software that we have invested significant amounts of time and money into developing and is now being made available to download, install, and be used by anyone for free. It supports all the functionality currently provided in Samourai Wallet.

Functionality

Provides unspent output lists to Samourai Wallet using your backing full node

Provides fee rates to use from your local mempool.

Mempool Orchestrator for time delayed transactions (Staggered Ricochet)

PushTX endpoint for broadcasting transactions through your backing full node

Support for tracking:

XPUB (BIP44)

YPUB (BIP49)

ZPUB (BIP84)

BIP47 loose addresses (P2PKH, Bech32)

Loose addresses (P2PKH, P2SH, Bech32)

How to get it?

We have worked hard to create a experience that is friendly to users with minimal technical experience. Installation is simple with a single automated script that will create and setup a full Dojo back end composed of:

a bitcoin full node accessible via an ephemeral Tor hidden service

database for storing addresses and transactions of interest

API accessible as a static Tor hidden service

A maintenance tool accessible through a Tor web browser

You can find detailed instructions for installing Dojo using this method on the Samourai Dojo Github repository. 

Users who rather have a plug and play experience will be happy to hear that we have partnered with Bitseed to provide top of the line hardware preloaded with Samourai Dojo. We are finalising the production of these high quality dedicated full nodes and they will be available for sale very soon.

Final thoughts

From our humble beginnings in 2015 as two passionate privacy activists working away on Samourai on nights and weekends at seedy London pubs we have promised two things:

Samourai will open source our back end servers allowing users to bypass our infrastructure entirely.

Samourai will remain in “unreleased” Alpha status until we do so. 

As an equally humble group of 6 privacy activists remotely working from seedy pubs around the world we have delivered on promise one. And we are now working steadily on graduating Samourai Wallet to full release 1.0

You may have noticed the UI changes in the wallet recently. These have been designed to be as friendly as possible to all the new users who are going to be joining the platform after 1.0 release, as well as be extendable as possible for all the functionality we have planned. There remains one final update before Samourai Wallet graduates to full release, and that is the ability to pair your wallet to your Samourai Dojo. You should expect this update any day now. 

From the entire Samourai Wallet team, we want to say thank you to our tens of thousands of testers who have each helped contribute to this moment. And to our haters who have relentlessly been spreading lies and FUD, GFY.  Cheers , The Entire Samourai Team

We are available as always to answer any questions on support.samourai.io or by email at support@samouraiwallet.com You can download Samourai Wallet from the Google Play Store

[samouraiwallet]

Collaborative Transactions - “Cahoots”

 I started to investigate the idea of nested / embedded transactions.You will find in the following notes some notes that can serve as a basis for the future.

LaurentMT April 17, 2018

Building on the shoulders of giants

The idea of nested / embedded transactions aren’t new. The earliest mention we can find dates to 2013 in a message board post by Greg Maxwell where he not only correctly describes the Common Input Ownership Heuristic that blockchain analysis firms use to create their data sets and cluster addresses – As Maxwell describes it, “A lot of people mistakenly assume that when a transaction spends from multiple addresses all those addresses are owned by the same party.”  – but also describes a practical method of multiple parties collaborating to create a transaction that breaks the heuristic above.

In April 2017, using the above message board thread as inspiration, we began work on a collaborative transaction framework, code name Cahoots. Cahoots will initially feature two different transaction types that make use of the idea of collaborating with other parties. The stated goal is to befuddle blockchain observers by tainting the heuristics they rely on. Additionally, Cahoots is an essential part of our post-mix strategy for our soon to be released Whirlpool mobile mixing solution.

STONEWALLx2

STONEWALLx2 builds on our existing STONEWALL transaction. The existing STONEWALL creates a transaction on the blockchain that simulates a CoinJoin transaction in a way that is mathematically indistinguishable from the real thing. A STONEWALLx2 makes use of a second party’s UTXO set in addition to your own to compose the transaction. The result is a high entropy “mini CoinJoin” transaction when sending to any third party. STONEWALLx2 is a great way to quickly mix on demand when sending to any third party by enlisting the help of a privacy conscious friend. 

Stowaway

Stowaway is a brand new transaction built on the Cahoots framework. Where both versions of STONEWALL are designed to look like CoinJoin transaction, a Stowaway is designed to blend in and look like a typical bitcoin transaction – with two inputs and two outputs – at the same time as keeping the amount sent when reviewing the transaction on the blockchain a secret. Unlike STONEWALLx2, Stowaway transactions can only be sent to the same person you are collaborating with. This makes Stowaway a great option for mixing when paying your privacy conscious friend. Maybe send a tip his way for helping out with your STONEWALLx2 transaction earlier ;)

Using Cahoots today

We’re still building out the full UI for Cahoots, so it is only available within Samourai Wallet as an “easter egg” for power users, or those who are eager to help test the bleeding edge. Full instructions for using collaborative Cahoots transactions with your privacy conscious friends on the bitcoin mainnet can be reviewed by following the links below:

Making STONEWALLx2 Transactions

Making Stowaway Transactions

The Future

The future is looking bright. Soon even the average user will be able to easily  mix their coins on a large scale basis with Whirlpool or on a per transaction basis with both Cahoots spend types described in this article.

Additionally, we’re not the only ones working on this type of technology. JoinMarket which can and should be regarded as an OG in the bitcoin privacy space have started work on a feature called “PayJoin” which is similar to Stowaway as an attack on the fundamental heuristics blockchain snoops employ. We encourage you to checkout a demo of PayJoin put together by Adam Gibson (Waxwing).

Putting all this together and a real Bitcoin privacy strategy starts to emerge. There isn’t a magic silver bullet to solve all our problems, a super weapon against the blockchain snoops doesn’t exist. What does exist are guerilla tactics by privacy extremists, where even the smallest minority - the individual - can make a large impact. Every Cahoots transaction is the equivalent of a drop of poison in the water supply of the enemy. With each transaction the snoops and observers lose a fundamental aspect of their analysis. The reliability of their data sets is diminished with each Cahoots transaction, benefiting every participant on the network. The snoops have been dealt a severe blow. They no longer know what they thought they knew.

Every transaction matters. Join the fight.

As always we appreciate your continued support of the project.We are available as always to answer any questions on support.samourai.io or by email at support@samouraiwallet.com

You can download Samourai Wallet from the Google Play Store

[samouraiwallet]

Staggered Ricochet, UTXO tagging, PayNym UX upgrades, and Whirlpool mixing prep

We are pleased to roll out Samourai Wallet update 0.99.05 available to update via Google Play for existing testers, install from Google Play for new testers, or build from source on Github. We will be releasing a direct download APK including Stealth Mode on GitHub in the coming days.

apk hash sha-256 of version 0.99.05 : 6bc4ad679d041e9d172fc2d91818c9335c0832d591864b617ff3c8b1fe49144f

Introducing Staggered Ricochet

We are very happy to release a long awaited upgrade to Ricochet - our premium transaction designed to increase the plausible deniability of your transactions by adding additional hops of history before the transaction reaches the final destination -  This upgrade is called Staggered Ricochet and helps decrease the fingerprint of Ricochet use by hostile exchanges and coin scoring platforms (currently not a known threat, but certainly a possible threat). Staggered Ricochet works by following two simple rules.

Rule 1 - Each Ricochet hop must be in a different block. Unlike a standard Ricochet which is broadcast using a time based delay, a Staggered Ricochet will broadcast a single transaction hop per block. This means a Staggered Ricochet can take up to two hours before reaching the final destination (depending on the time variance of blocks discovered).

Rule 2 - No transaction in the hop can be broadcast to the mempool at the same time. One of the clever ways of fingerprinting transactions that blockchain spies have been known to use is monitoring the mempool and using associated metadata including time first broadcast to assist in their address clustering heuristics. To help break that method Staggered Ricochet transactions will not be exposed to the public mempool until they are ready to be broadcast.

Staggered Ricochet is completely non custodial, just like standard Ricochet (you can recreate the private keys of the hops at any time) and is available to enable for no additional charge to any Ricochet transaction. Please be aware that Staggered Ricochet will take significantly longer to arrive at the final destination, so time sensitive transactions should continue to use standard Ricochet.

PayNym helper actions

One of the great benefits of using our PayNym technology is the reliable way to avoid reusing addresses (a privacy concern) with the ability to cryptographically generate addresses on behalf of your counterparty  without needing to communicate with them (a user experience concern). We have started to explore these concepts by adding convenience actions to the newly added Transaction Details screen for PayNym based transactions.

“Pay Again”

For outgoing PayNym transactions from your wallet - transactions you have sent - you will be able to initiate direct payment to the wallet with the address pre-filled. You can see how this type of functionality can be developed to encompass reoccurring non custodial payments without impacting your privacy. 

“Refund”

For incoming PayNym transactions into your wallet - transactions you have received - you will be able to initiate a return payment back to the sender wallet with the amount and address pre-filled. You can see the power such a feature can enable with a little development, especially for dynamic street merchant use.

UTXO Tagging and Whirlpool prep

We have added the ability to tag any UTXO with a custom value. This can be useful for noting UTXOs that you may want to avoid spending, or the need to add any additional meta data. These tags are local and will be lost if you restore from mnemonic + passphrase, so you should restore via your automatic encrypted backup whenever possible. You can currently tag UTXOs from the Unspent Output list and will be expanded upon in coming updates.

For TestNet users: we have added in PSBT support to compliment upcoming Whirlpool mixing and other post-mix transaction types such as 2-Person STONEWALL and Stowaway. Bleeding edge testers will be able to manually compose collaborative testnet Stowaway transactions using the tools found in Settings. We anticipate advancing this to MainNet in the next releases.

As always we appreciate your continued support of the project.

We are available as always to answer any questions on support.samourai.io or by email at support@samouraiwallet.com

You can download Samourai Wallet from the Google Play Store

[samouraiwallet]

Temporarily disabling Stealth Mode, Remote SMS, and SIM Switch Defense features due to restrictive Google Play Store policies.

It is with great sadness that we are disabling the following features within Samourai Wallet as of version 0.99.04 - which will be released tomorrow - due to new extremely restrictive policies Google has decided to introduce in their effort to become more of a “walled garden” experience:

Stealth Mode

SIM Switch Defense

Remote SMS Commands

All three of these features have been included in Samourai Wallet since our first release in 2015 and have helped define our product as a unique offering instead of the same old lazy copy paste job that is rife in this industry, as well as provide protection and security to the countless users who rely on these features. To this day no other wallet has enabled these types of features, and now it is very likely no other wallet will thanks to the heavy hand of Google.

We applied for an exemption with Google months ago, which was rejected days ago, despite our argument that removing such functionality would cause users who rely on those features to be less secure and more exposed. We also provided evidence of the SIM Switch Defense feature alerting users countless times to attempted SIM Swap attacks on their SIM Cards. It made us very proud that our little feature was protecting users from the horrible OpSec of network carriers which allow SIM Swap attacks to occur. Google does not care about any of this however, and Samourai Wallet would have been removed from the Google Play Store had we not complied with this dictate.

In the coming months we will expand our distribution model to include self hosted APK downloads and inclusion in the open source F-Droid app store. These versions will all include the Stealth Mode, Remote SMS, and SIM Switch Defense features.

In the meantime users should disable Stealth Mode prior to updating to version 0.99.04 or contact us at support@samouraiwallet.com if you have already updated and now are having trouble accessing your wallet so our support agents can assist you.

Again, we are sorry for this inconvenience, but our hands have been tied by Google. We hope to bring these features back somehow in the future in the Google Play Store release, and are dedicated to offering the full feature set experience via alternative distribution methods such as direct download and F-Droid in the coming months.

[samouraiwallet]

0.99 - UI and fee management updates

We are pleased to roll out Samourai Wallet update 0.99 available to update via Google Play for existing testers, install from Google Play for new testers, or build from source on Github. apk hash sha-256 of version 0.99 : d3c0f83f915daa5e9a57a79d0460d5050786409a70916c13fd59b25129a20989

Transaction Details

We’re really excited to implement the long requested Transaction Details screen. This view allows you to gain important information about your transactions without having to leave the wallet. Simply tap the transaction from the balance screen to open the transaction details view. From this screen you can boost the transaction fee of unconfirmed transactions as well as review transaction details such as the fee rate paid. You can always open the transaction in OXT mobile block explorer by pressing the compass icon in the top right of the toolbar.

Improved Sending Experience

The send bitcoin screen hasn’t changed too much since we first released Alpha 1 in 2015. Since then we have been stuffing all sorts of advanced functionality into a UI that was struggling to keep up. This is why we took the opportunity to rethink the Send Bitcoin process and create an experience that would be extensible as we grow our feature set and more user friendly for our users today and our future users tomorrow.

What was previously crammed into one screen we have now broken down into two separate steps. First, select who you want to send bitcoin to and select how much you want to send in BTC or Satoshis (sats). If you’re sending to a centralized exchange/service you may want to enable Ricochet for added protection from third party blacklists, which you can do from this screen.

The second step is where you review the transaction that will be sent. You can adjust the transaction priority - which determines how quickly your transaction gets added to a block - by sliding from left (lowest priority and lowest fee) to right (highest priority and highest fee) - If your wallet can send the transaction as a STONEWALL it will be enabled here, which you can toggle on/off on a per transaction basis. If a STONEWALL cannot be created, this option will be disabled. 

As always we appreciate your continued support of the project.

We are available as always to answer any questions on support.samourai.io or by email at support@samouraiwallet.com

You can download Samourai Wallet from the Google Play Store

[samouraiwallet]

Retiring Afterburner

First a little history for the newer bitcoin users.

Though 2017 wasn’t that long ago, the landscape of Bitcoin was very different than it is today. Segwit was not yet activated on the network, almost all popular wallet software didn’t allow users to set custom miner fees, and very few allowed users to send with the useful Replace By Fee flag on their transactions. These shortcomings in the most popular and well funded wallets in combination with a long sustained politically motivated spam attack on the bitcoin network, contributed to the degradation of the bitcoin experience for many thousands of users and was a substantial factor in the artificial dramatic increase in transaction fees in 2017.

While the larger venture capital backed wallets decided to use this time to turn their back on Bitcoin, we at Samourai decided to incorporate the tools users needed to navigate the new realities of the network. During this event we improved our fee estimation, introduced custom fees, implemented batch spending, implemented Replace By Fee for topping up miner fee on transactions sent, and CPFP for topping up miner fees on transactions they received. So, while Samourai users were largely shielded from the worst of the impact, many many more users were stuck using inferior wallet software.

On June 15, 2017 we released Bitcoin Afterburner on the Google Play Store. Afterburner was designed to help non Samourai Wallet users boost their stuck bitcoin transactions using the advanced tools unavailable in their wallet. Afterburner boosted many stuck bitcoin transactions shortly after release - helping bitcoin users make the transactions they needed to make -  but more importantly, it shifted the wider discussion within the context of what is the minimum functionality a wallet should provide users. Users started to demand more control over their transactions. We see this as a huge victory for bitcoin users as most major wallet providers now allow users to set custom miner fees, and some have implemented RBF and CPFP fee boosting features.

Today we are saluting Bitcoin Afterburner for its service and retiring it from active duty. To all those who used Afterburner to boost their stuck transaction, you played a part in showing the major venture capital backed wallet providers that they needed to change and listen to their users, and thus you helped make Bitcoin better for those who came after you. If we need to remind them again in the future we won’t hesitate to bring to bring Afterburner back into active duty. Afterburner will be removed from the Google Play Store as of October 11th 2018, but will remain available, fully open source, on our Github repository.

[samouraiwallet]

0.98.87 - Welcome new international users, and saying adieu to fiat currency.

We are very pleased to roll out Samourai Wallet update 0.98.87 available to update via Google Play for existing testers, install from Google Play for new testers, or build from source on Github. 

apk hash sha-256 of version 0.98.87 : 861c5b709173fbaab897a11d2991c6c4112a633173ed7b6d4a766257a9914f91

Translations

We firstly want to shout out the fantastic Samourai community for their drive to provide high quality localisation for Samourai Wallet and Sentinel. It is because of their determination and support of our mission to create a more private bitcoin that Samourai Wallet is now available in 12 languages (see the full list at the bottom of this post) with French and Chinese added in this release. These aren’t generic computer translations, these are translations by actual bitcoin users from the local region, and as such are extremely high quality and contextual. 

We have already seen the side effects with installs increasing dramatically from international user bases with a native translation, usually in places where they need Samourai the most. If you would like to offer a translation for Samourai Wallet into your own language, or would like to improve an existing translation you can follow this guide.

Farewell fiat

“We believe it is fundamental that our existing and future users understand that when they transact within the Bitcoin network, when they participate in the Bitcoin economy, they are transacting with the token native to that network, BTC, and nothing else.” 

In 2015 when we first launched Samourai Wallet, we reasoned that a fiat based conversion rate would be a convenient feature for users who wished to have a rough idea of what their BTC stash was worth in fiat currency at any given time. We said “users aren’t ready” to give up fiat in the wallet, and we ended up including what we called the “Street Price” - the fiat conversion rate as provided by exchanges and services without KYC/AML requirements - and left it at that.

In 2017 we noticed a disturbing trend within the wider community. Many news outlets, data providers, prominent persons, and innocent users started to refer to bitcoin transactions in USD terms instead of BTC terms. Prominent altcoin proponent Roger Ver noted to his 500k Twitter followers that “TX fees SKYROCKET to $55/TX”, he of course knows better and was maliciously spreading propaganda to further his agenda, but the damage was done. Since then we have noticed many bitcoin users innocently noting their wallet balance, amounts sent, and miner fees in fiat currency instead of BTC. We spent many hours a week in our support channels explaining to confused and concerned users why they had 8 USD yesterday and 7 USD today. We reasoned that “Users aren’t ready” to give up thinking in fiat terms, and with education they would eventually change.

We are now nearing the end of 2018 and realize that users will never be ready. Thinking in fiat currency terms is familiar, you likely interact with it all the time. This is precisely the reason that within the context of a Bitcoin wallet it is a crutch. We have made the decision that as of version 0.98.87 to remove that crutch. All fiat currency conversions have been removed from Samourai Wallet. We understand this may inconvenience some, it may even be enough to cause us to lose some users, but we believe it is fundamental that our existing and future users understand that when they transact within the Bitcoin network, when they participate in the Bitcoin economy, they are transacting with the token native to the Bitcoin network, BTC, and nothing else.

We have decided to keep fiat currency conversion within the Sentinel Watch Only app, as independent merchants who frequently use the app and other use cases require the use of a currency conversion function. 

Hello satoshi

The smallest unit of bitcoin is called a ‘satoshi’ or ‘sat’. 1 sat is equal to 0.00000001 BTC. When you tap your balance in your Samourai Wallet instead of the fiat currency conversion your wallet will convert to display in satoshi units. 

As always we appreciate your continued support of the project. 

We are available as always to answer any questions on support.samourai.io or by email at support@samouraiwallet.com

You can download Samourai Wallet from the Google Play Store

Full list of supported languages and their translator(s)

Brazilian Portuguese (Rayserzor)

Bulgarian (Relaxo143)

Chinese (rbensberg)

French (deBeauvoir)

German (michaelWuensch)

Indonesian (eb-ina)

Italian (LifeIsPizza)

Portuguese (ric2b)

Russian (engenegr,nvyo)

Spanish (eMaringolo)

Turkish (yilmzfurkan)

[samouraiwallet]

The Road to 1.0 - UI Update

We are very pleased to roll out Samourai Wallet update 0.98.75 available to update via Google Play for existing testers, install from Google Play for new testers, or build from source on Github. This update includes two important UI changes and very important under the hood changes for the future. 

apk hash sha-256 of version 0.98.75 : 70d609cdf5a9bd130543b30853268b6783f8b90ed38fd48838e942ad5b1fff6c

These UI and UX modifications are the first of many to help prepare Samourai Wallet for 1.0 release later this year. 

Real-time transaction state

After a normal spend, a STONEWALL spend, or a batch spend you will now see a full screen overlay of the current state of the transaction in real-time. Our valued Ricochet users will see a modified animation specific to Ricochet in a future update. 

Creating transaction The wallet is gathering the needed inputs to cover the full amount to be spent and composing an unsigned transaction. 

Signing transaction The wallet is signing the transaction it just created with the necessary private keys of the selected inputs.

Broadcasting transaction The wallet is broadcasting the signed transaction either via our Iceland based Bitcoin Core node or your own Trusted Node.

Transaction Sent The transaction has been submitted to the bitcoin network for inclusion in the blockchain.

This screen becomes even more important as we begin to roll out Offline Mode where user intervention needs to take place between Transaction Signing and Broadcasting. Consider this new real time status animation this a nice visual treat with a deeper future purpose. 

Simplified Receive Screen

The other change you will immediately notice is the simplified receive screen.

The current address is now directly at the top of the screen. You can still tap this address to copy it to your clipboard, and you can share the address using a variety of methods using the Share icon in the toolbar. 

Tap the advanced toggle to create a QR code with a BTC amount encoded within it or to change the type of address to use. By default, Segwit Compatibility addresses are displayed. Allowing you the benefits of Segwit, while still producing addresses that older wallets understand. 

Samourai Wallet users can produce Legacy addresses that begin with a “1″, Segwit Compatibility addresses that begin with a “3″, or Segwit Native addresses that begin with a “bc1″. 

We have also added in the derivation path of the displayed address for our power users. 

Send Screen

We have made a minor change to the send screen in this update after receiving a lot of feedback from our regular Ricochet users. The Ricochet toggle will now remember the last state it was in. This means, if you enable Ricochet, the next time you visit the send screen, Ricochet will be enabled.

The next UI update will include significant UI changes to the existing send screen.

Unseen Changes

An important under the hood change in the way your wallet keeps track of PayNym’s means your PayNym bot will very soon generate Segwit Native (bech32) addresses by default instead of legacy addresses. This change, in combination with many more planned updates will make using PayNym’s cheaper, faster, and easier than ever. 

We hope you enjoy this update and the new UI changes.The latest version of Samourai Wallet can be installed onto your Android device from the Google Play Store.

We are available to provide support at support.samourai.io or by email at support@samouraiwallet.com

[samouraiwallet]

Full bech32 support, introducing Boltzmann and STONEWALL, enhanced Ricochet transactions, and more..

We are very happy to announce the release of Samourai 0.98.5 available to update via Google Play for existing testers, install from Google Play for new testers, or build from source on Github. This update is filled with new functionality and improvements, so let’s get right into it.

sha-256: da8f64dab248447e1acc02a6f41d91a0570a7990de724987be992720838e1511

Full bech32 support

Bech32 is the native way of encoding segwit bitcoin addresses. Samourai Wallet is now fully compliant with BIP84 - which means you are now able to send externally to bech32 encoded addresses as well as receive to your own bech32 encoded addresses.  A bitcoin address encoded with bech32 starts with bc1 and is not backwards compatible with older/unmaintained software and wallets. It may take a while for bech32 support to fully roll out across other wallets and services. For this reason, your Samourai wallet will still generate segwit addresses that are backwards compatible with all bitcoin wallets (these addresses start with a 3) by default. You can easily reveal a bech32 address directly from the wallet Receive screen.

Introducing Boltzmann and STONEWALL

Since December 2017, when  Samourai acquired the OXT block exploration platform, we have been working closely with OXT privacy and fungibility engineers to audit the transactions that Samourai Wallet creates, looking for fingerprints and metadata that could be extracted from public transaction data by blockchain analysis companies. One part of this audit process involves running transactions through a script called Boltzmann - Boltzmann returns the entropy of the transaction which measures the linkability of inputs to outputs of a given transaction by determining the number of individual mappings of the inputs to outputs used in the transaction. The higher the entropy of a transaction, the more resistant to address/identity clustering techniques used by Blockchain analysis companies - as the element of doubt connecting ownership of addresses by any entity is too great, and may pollute the entire cluster.

More in depth information about Boltzmann can be found in three parts by the author and maintainer of the project: Part 1, Part 2, and Part 3.

As part of the ongoing audit we identified a potential shortcoming which may lead to less entropy than expected when sending via BIP126. BIP126 was inspired by the Samourai Alpha 1 “decoy change addresses” feature and introduced refinements to improve efficiency of the feature. As our understanding of the latest analysis techniques further evolves, the need to stay on the cutting edge of careful coin selection and transaction manipulation increases in importance. 

As such, we are retiring BIP126 from Samourai Wallet and we are happy to introduce STONEWALL in replacement.. STONEWALL is a new send type available at no extra charge to all Samourai users, enabled by default - it can be disabled in the Transaction Settings. Whenever possible your wallet will create transactions that simulates a CoinJoin transaction and obtains a Boltzmann score greater than 0. Transactions will appear on the blockchain as if there are multiple unrelated counterparties involved. STONEWALL improves on BIP126 in a number of ways. Primarily, STONEWALL activates more frequently than BIP126 did, meaning more of your transactions will benefit from this type of protection. Additionally, the entropy of STONEWALL transactions have been consistently higher than BIP126 transactions during our testing. Specific STONEWALL Algorithm information can be reviewed here.

Samourai is committed to continuing the investment and development of STONEWALL,  Boltzmann and other open source research and development projects maximising privacy and fungibility of bitcoin users. Samourai users will see further integration with Boltzmann in the near future, including the ability to measure the entropy of transactions before they are broadcast directly in the wallet. You can review the entropy of your bitcoin transactions today by searching for your transaction using the OXT Block Explorer. We look forward to polluting the datasets of blockchain analysis companies and stone-walling their efforts to debase the fungibility of the bitcoin token and the privacy of the bitcoin user.  

Ricochet Enhanced

Ricochet is one of our most popular features, and with good reason. Ricochet provides a good layer of protection from “blanket blacklists”. Blanket blacklists are a very primitive - and stupid - form of blockchain analysis relied upon by many exchanges that deal with Fiat currency. The blacklists are informed by looking at the “history” of coins going back 4-5 hops, and marking those coins “High risk” if someone at some point in time did something the company ‘analyzing’ disagrees with. This form of blanket blacklisting results in many innocent users having their accounts shut down for seemingly no reason. Ricochet adds additional “hops” of address history between your initial sending address and the final destination address. Today we are happy to announce that we have updated Ricochet to use native segwit bech32 addresses for all the hop transactions. This results in lower total miner fees for Ricochet users.

Ricochet users who have taken the additional step of connecting to the Samourai Donations PayNym will see increased privacy benefits when sending via Ricochet with the introduction of a new algorithm that reduces the fingerprint of the ricochet transaction on the blockchain. It is highly encouraged to connect to the Samourai Donations PayNym for a big Ricochet privacy boost and enhanced protection from blanket blacklists.

Stability and Android battery warning

Last but not least, we have made many modifications to the underlying Samourai architecture to improve the stability of the wallet. Specifically, loading times and the responsiveness after sending and receiving should be improved for all users.

Due to recent changes in Android 8, some users were impacted by force closes and general stability issues. This update includes significant refactoring of core services, which should clear up a lot of issues Android 8 users were experiencing. This is a work in progress, if you experience any issues please do not hesitate to contact support@samouraiwallet.com for help, support, or to report a bug.

Another Android 8 specific issue is a persistent (and incorrect) warning that Samourai is using too much battery impacting some users. This is again due to changes in Android 8 which target background services. We are making the needed changes as requested by the new Android guidelines, but they will not be ready until the next update. You can confirm the battery warning is erroneous by viewing more details and verifying the battery usage amount since the last full charge of the device.  

[samouraiwallet]

Introducing batch spending for cheaper, more efficient bitcoin transactions

One of the most requested features our users have recently been asking for is the ability to combine (or batch) multiple unrelated spends into one transaction. The benefit to creating these combined transactions is much lower overall fees and more efficient use of the bitcoin blockchain. 

Well, you spoke and we listened. In version 0.97.35 of Samourai Wallet, users will have the option of a selecting a new custom send type, “Batch Spend”

Who is this useful for?

This feature is useful for any user who needs to make more than 1 transaction in a given time period. 

For example, if Alice needs to pay both Bob and Charlie, she can combine both payments into one transaction, and pay one miner fee. Bob and Charlie get paid as usual, and Alice just saved herself an unnecessary fee. 

Samourai Wallet users are already paying the lowest transaction fees of any other wallet, but now they can save up to 80% on bitcoin miner fees by using our new Batch Spend feature.

Add transactions throughout the day. Spend when you’re ready.

Another great use case for Batch Spend is low priority transactions. These can be transactions to yourself or your friends, consolidation transactions, or any transaction that is non urgent. Add transactions throughout the day (or week, or month, or year!) to your Batch Queue which will remain saved until you manually clear the queue or broadcast the transaction.

What a Batch Spend looks like

Today, in anticipation of this update we asked our fantastic community on Twitter to provide a bitcoin address. We then took the first 15 addresses and created the a batch spend from Samourai on the bitcoin mainnet. You can view the transaction on our OXT block explorer.

As you can see, we paid a total of 0.00003040 BTC  (roughly 20 cents, at the time of TX)  to send to 15 unrelated participants. The transaction confirmed within 7 blocks. Totally badass.

We hope you enjoy this update and the new functionality. Batch Spend is available in the latest version of Samourai Wallet which can be installed onto your Android device from the Google Play Store

We are available to provide support at support.samourai.io or by email at support@samouraiwallet.com

[samouraiwallet]

Bitpay QR codes are no longer valid. Important Notice.

Very recently and without much notice or discussion with developers, one of the largest Bitcoin payment processor for merchants, Bitpay, decided to drop support entirely for the bitcoin standard scheme for displaying a payment request to an end-user known as BIP21. In replacement of BIP21 - which is universally supported and implemented by all Bitcoin wallet and service providers since 2012 - Bitpay will present a payment request to users that conforms to a controversial proposal that is not widely supported (BIP 70).

What is BIP21?

BIP21 is an open standard deployed and enabled by all bitcoin wallets and services since 2012. Following the rules laid out in BIP21 ensures that no matter the wallet software or service used, the QR code and payment request must be created and interpreted in one standard way. This ensures maximum compatibility and interoperability between software and services all operating in a decentralized open source network. Needless to say, Bitpays decision to drop all support for this fundamental open standard, will harm the overall user experience not improve it, as they claim to be striving for.

What is Bitpay’s Payment Protocol?

Bitpay has replaced BIP21 entirely with different, more controversial proposals, BIP’s 70,71,72. BIP70 was originally proposed by Gavin Andresen and Mike Hearn in 2013 - who championed creating bitcoin blacklists - generated a lot of controversy and remains largely unadopted by the majority of wallet and service providers due to many security and privacy concerns.

BIP70 introduces the requirement on developers to support legacy public-key infrastructure dependencies with known track records of vulnerabilities (openssl and heartbleed, etc...). Additionally, widespread implementation of BIP70 introduces an exposure to increased risk of AML/KYC surveillance and monitoring of on-chain transactions and more effective blacklists.

Moving forward

We have to be very clear here. Samourai Wallet will not support BIP70 in our products, therefore, our wallet users will NOT be able to send bitcoin to QR codes generated by Bitpay invoices, as they do not provide a valid Bitcoin address. If you want to make payments to a QR code provided by Bitpay you will need to use a wallet that has enabled BIP70.

We absolutely do not support Bitpay in agressively using their dominant position of market share to bully wallet providers into supporting their business plans or bully users into a system that degrades their privacy and the fungibility of bitcoin as a whole. Bitpay should focus on repairing their image and brand after the cataclysmic failure of the Segwit2x Fork they helped architect, instead of reinforcing their image as an out of touch bully looking to hijack the network for their own gain.

Users should stand up to this kind of arrogance and stand up for their privacy. Samourai has already started the process of contacting all vendors we rely on who utilize BitPay as a payment processor and informing them of our intention to switch vendors, as using Bitpay is no longer tolerable or feasible. We hope others join us.

We are available as always to answer any questions on support.samourai.io or by email at support@samouraiwallet.com

[samouraiwallet]

Samourai + OXT

Today we have an announcement that is a little bit different than our usual wallet updates, but we hope you’ll share in our excitement. We are very happy to announce that Samourai has finalized the acquisition of the blockchain explorer, visualization tool, and analysis platform OXT.me in an all BTC transaction. If you haven’t tried out OXT yet, do yourself a favor, and give it test drive.It isn’t only visually beautiful, it is packed with great information and insight into the public bitcoin ledger.

OXT has been an under appreciated asset in the Bitcoin ecosystem for years. They have been providing the same caliber of professional analysis, visualization, and exploration tools used by top researchers, multinational corporations, and even law enforcement to the broad general public in a free and open manner.

Using the OXT platform, the team have been able to produce research that can help measure and improve the financial privacy of users throughout the entire ecosystem, they have discovered important information about the ongoing spam attacks on the bitcoin network, and they have created open source actionable tools for measuring plausible deniability of transactions on the blockchain. 

We are of course looking forward to the addition of an incredibly sophisticated blockchain explorer and visualization platform to our offering and all the possibilities that will open up to our users, but the insights and research that the OXT team is able to derive from the platform is beyond priceless. Samourai will continue to make even better, more private, and more user friendly products with OXT on board.

OXT will continue to be operated by the existing team and will remain a separate, yet complimentary entity of Samourai. OXT will continue to offer open access to all the data on the entire bitcoin blockchain to the general public, for free, and will continue to produce open source research and analysis made available to the community. Samourai is very much born of the cypherpunk spirit. Spurning traditional venture capital investment, the company is self funded and supported by key private individuals who are dedicated to the goals of open access to data, freedom of speech, and censorship free financial transactions. We see this acquisition as a long term strategic investment in both Samourai and OXT, in these ideals, and an in the community as a whole.

We thank our users, and the fantastic community that has grown around Samourai, and we hope that you extend a warm welcome to OXT as they join us. 

[samouraiwallet]

Wallet Update 0.97 - Coin Control, Dust TX alerts, Like-Type inputs and more.

It’s that time again, a new Samourai Wallet update has just hit the Google Play store and is available for download on your Android device right now. As always the full list of changes is available on GitHub. We’re really excited about this release because it lays the foundation for a lot of exciting features coming down the line. 

Coin Control

Coin Control is a powerful feature and nearly unheard of in most Bitcoin wallet software. To understand coin control, you first have to understand a little how your bitcoin wallet works under the hood. Samourai Wallet gives you access to a list of ‘Unspent Outputs��� in your wallet. Unspent outputs, are simply put, bitcoin in your wallet that can be spent as part of a new transaction. The combined amount of unspent outputs is equal to your total spendable balance. So if you have 2 Unspent Outputs of 0.5 BTC - your wallet would have a total spendable balance of 1 BTC. Coin control refers to the user having optional control over which unspent outputs get used when creating new transactions. 

As of version 0.97, users will be able to mark any unspent output in their wallet as ‘Do Not Spend’. Any Do Not Spend output will not display as part of the total balance of the wallet and will not be used to create new transactions. The Do Not Spend tag is reversible at any time. 

Blockchain Fungibility with like-type inputs and outputs 

In the last update (v 0.96) we introduced the concept of matching like-type outputs when creating transactions on the blockchain. This meant, that if you were sent bitcoin to an address beginning with ‘3′ then the returning ‘change’ output will also be sent to an address in your wallet that begins with a ‘3′. 

As of version 0.97 released today Samourai now will always attempt to create transactions with like-type inputs in addition to like-type outputs. This takes the anti fingerprinting measures a step further by making it incredibly difficult to link the sending addresses to the receiving addresses in a transaction on the blockchain, throwing a wrench in ways spies and snoops track the blockchain. 

Dust Tracking Real Time Alerts

Speaking of blockchain snoops and spies... One of the methods in use to de anonymise bitcoin users is through a process called ‘Dusting’. When you’re Dusted you’ll receive a small bitcoin transaction into an address in your wallet. Eventually your wallet will combine this small amount of BTC into a larger transaction and reveal other addresses that can be linked to you with certainty, building a network graph of your wallet and transaction history. 

In this version of Samourai Wallet, we have added real time Dust Alerting. If you wallet receives a low value transaction (anything less than 1000 satoshis) you will be alerted and given the choice to mark the dust output as ‘Unspendable’. If you see this alert and you weren’t expecting the incoming deposit we recommend blocking the transaction for your privacy. As always, the Unspendable tag is reversible if you decide to change your mind later. 

Gifts for our power users

Some new tools our dedicated power users may find useful:

Raw PushTX Push any signed transaction (hex format) to the bitcoin network - Available in Settings > Transactions > Broadcast Transaction Hex

Sign message with Segwit address Sign any message with an active segwit (P2SH-P2WPKH) utxo privkey

Show redeem script of Segwit utxo    

For our users who are keeping track, the SHA-256 APK hash for this release is: 2270e7c9b402447e5cc881f9d3eea4e5c72c08c55c47c70df0d3bf16cb5a6123 You can verify this matches the hash of your own wallet by navigating to the Settings > About > APK Hash screen

You can get help and support from support.samourai.io or by emailing support@samouraiwallet.com 

[samouraiwallet]

Wallet Update - Segwit support and introducing MuleTools

Last week we released Samourai Wallet version 0.96 on the Google Play store. The full list of changes can be viewed on GitHub and includes many improvements and fixes. However, we want to focus on two main areas in this post. One area you all have heard of and been asking for, and one we want to introduce you to.

Segwit

Samourai Wallet has now fully integrated the changes needed to implement support for the latest bitcoin upgrade, Segregated Witnesses. By default all addresses you reveal through the receive screen will be P2SH-P2WPKH as defined by BIP141 and BIP49. We’ll refer to these as ‘segwit addresses’ for simplicity sake, but make no mistake, these are normal bitcoin addresses and are compatible with the Bitcoin reference client since version 0.6.0. These addresses are more efficient to transact with and users can expect to pay lower fees when spending from segwit addresses. Segwit support is enabled by default but can be disabled within the wallet settings or on a one-off basis with a convenient toggle switch directly on the Receive screen.

For the more technical users, your P2SH-P2WPKH and your P2SH inputs remain in a single HD account and can be mixed together in a transaction thanks to the wallet being able to sign mixed inputs. Your wallet will now have two Extended public keys (xpub) - so, if you are a Sentinel user you will need to add your BIP49 xpub along with your BIP44 xpub. Both of your xpub’s can be found  in the settings. Samourai will manage the creation of either P2SH or P2SH-P2WPKH change outputs depending on the type of output being spent to. This is to decrease the fingerprint of the transaction on the block chain.

MuleTools

We’re happy to make public an initiative we have been thinking about for some time. Inspired by the Blockstream satellite and the 2003 essay by Nick Szabo, Advances in Distributed Security MuleTools is the umbrella term for the open repository of community ideas and open source code that promotes alternative routes for bitcoin broadcasts and block retrieval. Having many different options for interacting with the bitcoin network greatly increases the censorship resistance of the network and the financial autonomy of the user.

Samourai is interested in assisting with the development of any alternative paths for bitcoin pushTx and block retrieval and will consider all submitted projects for possible inclusion within Samourai Wallet.

Pavol Rusnak developed a simple PushTx server to push transactions to the bitcoin network via SMS and Andrew LeCody created a proof of concept APRS pushTx server for pushing transactions over shortwave radio. We think these both are a great example of an alternative method of pushing transactions. Inspired by the work of these developers, Samourai Wallet now includes the ability to export a signed raw bitcoin transaction hex or QR code that can be fed by the user to any pushTx server.

We look forward to exploring this concept further, hopefully with community feedback and support. Please feel free to check out the MuleTools readme, submit issues, ideas, pull requests, or documentation on the repositories. Any individual or company who wishes to collaborate is encouraged to reach out.