#Caesar cipher for beginners

[presswoodterryryan]

Unlocking Ancient Secrets: Master Code Creation

By Ariel Imagine you’re a spy in ancient times, carrying an important message that must stay hidden from enemies. How would you keep it safe? Have you ever wanted to send a secret message to a friend? Or crack a hidden code like a real-life detective? Secret codes have been used for thousands of years to protect important messages. Today, I’m going to take you on an adventure through history,…

[blubberquark]

Why Not Write Cryptography

I learned Python in high school in 2003. This was unusual at the time. We were part of a pilot project, testing new teaching materials. The official syllabus still expected us to use PASCAL. In order to satisfy the requirements, we had to learn PASCAL too, after Python. I don't know if PASCAL is still standard.

Some of the early Python programming lessons focused on cryptography. We didn't really learn anything about cryptography itself then, it was all just toy problems to demonstrate basic programming concepts like loops and recursion. Beginners can easily implement some old, outdated ciphers like Caesar, Vigenère, arbitrary 26-letter substitutions, transpositions, and so on.

The Vigenère cipher will be important. It goes like this: First, in order to work with letters, we assign numbers from 0 to 25 to the 26 letters of the alphabet, so A is 0, B is 1, C is 2 and so on. In the programs we wrote, we had to strip out all punctuation and spaces, write everything in uppercase and use the standard transliteration rules for Ä, Ö, Ü, and ß. That's just the encoding part. Now comes the encryption part. For every letter in the plain text, we add the next letter from the key, modulo 26, round robin style. The key is repeated after we get tot he end. Encrypting "HELLOWORLD" with the key "ABC" yields ["H"+"A", "E"+"B", "L"+"C", "L"+"A", "O"+"B", "W"+"C", "O"+"A", "R"+"B", "L"+"C", "D"+"A"], or "HFNLPYOLND". If this short example didn't click for you, you can look it up on Wikipedia and blame me for explaining it badly.

Then our teacher left in the middle of the school year, and a different one took over. He was unfamiliar with encryption algorithms. He took us through some of the exercises about breaking the Caesar cipher with statistics. Then he proclaimed, based on some back-of-the-envelope calculations, that a Vigenère cipher with a long enough key, with the length unknown to the attacker, is "basically uncrackable". You can't brute-force a 20-letter key, and there are no significant statistical patterns.

I told him this wasn't true. If you re-use a Vigenère key, it's like re-using a one time pad key. At the time I just had read the first chapters of Bruce Schneier's "Applied Cryptography", and some pop history books about cold war spy stuff. I knew about the problem with re-using a one-time pad. A one time pad is the same as if your Vigenère key is as long as the message, so there is no way to make any inferences from one letter of the encrypted message to another letter of the plain text. This is mathematically proven to be completely uncrackable, as long as you use the key only one time, hence the name. Re-use of one-time pads actually happened during the cold war. Spy agencies communicated through number stations and one-time pads, but at some point, the Soviets either killed some of their cryptographers in a purge, or they messed up their book-keeping, and they re-used some of their keys. The Americans could decrypt the messages.

Here is how: If you have message $A$ and message $B$, and you re-use the key $K$, then an attacker can take the encrypted messages $A+K$ and $B+K$, and subtract them. That creates $(A+K) - (B+K) = A - B + K - K = A - B$. If you re-use a one-time pad, the attacker can just filter the key out and calculate the difference between two plaintexts.

My teacher didn't know that. He had done a quick back-of-the-envelope calculation about the time it would take to brute-force a 20 letter key, and the likelihood of accidentally arriving at something that would resemble the distribution of letters in the German language. In his mind, a 20 letter key or longer was impossible to crack. At the time, I wouldn't have known how to calculate that probability.

When I challenged his assertion that it would be "uncrackable", he created two messages that were written in German, and pasted them into the program we had been using in class, with a randomly generated key of undisclosed length. He gave me the encrypted output.

Instead of brute-forcing keys, I decided to apply what I knew about re-using one time pads. I wrote a program that takes some of the most common German words, and added them to sections of $(A-B)$. If a word was equal to a section of $B$, then this would generate a section of $A$. Then I used a large spellchecking dictionary to see if the section of $A$ generated by guessing a section of $B$ contained any valid German words. If yes, it would print the guessed word in $B$, the section of $A$, and the corresponding section of the key. There was only a little bit of key material that was common to multiple results, but that was enough to establish how long they key was. From there, I modified my program so that I could interactively try to guess words and it would decrypt the rest of the text based on my guess. The messages were two articles from the local newspaper.

When I showed the decrypted messages to my teacher the next week, got annoyed, and accused me of cheating. Had I installed a keylogger on his machine? Had I rigged his encryption program to leak key material? Had I exploited the old Python random number generator that isn't really random enough for cryptography (but good enough for games and simulations)?

Then I explained my approach. My teacher insisted that this solution didn't count, because it relied on guessing words. It would never have worked on random numeric data. I was just lucky that the messages were written in a language I speak. I could have cheated by using a search engine to find the newspaper articles on the web.

Now the lesson you should take away from this is not that I am smart and teachers are sore losers.

Lesson one: Everybody can build an encryption scheme or security system that he himself can't defeat. That doesn't mean others can't defeat it. You can also create an secret alphabet to protect your teenage diary from your kid sister. It's not practical to use that as an encryption scheme for banking. Something that works for your diary will in all likelihood be inappropriate for online banking, never mind state secrets. You never know if a teenage diary won't be stolen by a determined thief who thinks it holds the secret to a Bitcoin wallet passphrase, or if someone is re-using his banking password in your online game.

Lesson two: When you build a security system, you often accidentally design around an "intended attack". If you build a lock to be especially pick-proof, a burglar can still kick in the door, or break a window. Or maybe a new variation of the old "slide a piece of paper under the door and push the key through" trick works. Non-security experts are especially susceptible to this. Experts in one domain are often blind to attacks/exploits that make use of a different domain. It's like the physicist who saw a magic show and thought it must be powerful magnets at work, when it was actually invisible ropes.

Lesson three: Sometimes a real world problem is a great toy problem, but the easy and didactic toy solution is a really bad real world solution. Encryption was a fun way to teach programming, not a good way to teach encryption. There are many problems like that, like 3D rendering, Chess AI, and neural networks, where the real-world solution is not just more sophisticated than the toy solution, but a completely different architecture with completely different data structures. My own interactive codebreaking program did not work like modern approaches works either.

Lesson four: Don't roll your own cryptography. Don't even implement a known encryption algorithm. Use a cryptography library. Chances are you are not Bruce Schneier or Dan J Bernstein. It's harder than you thought. Unless you are doing a toy programming project to teach programming, it's not a good idea. If you don't take this advice to heart, a teenager with something to prove, somebody much less knowledgeable but with more time on his hands, might cause you trouble.

[arcturianview]

i finally sat down and finished deciphering the cipher from the Bridon Arc OP. im aware its been deciphered since the day the OP was released, but i wanted to do it myself and i only really locked in on it tonight. i had fun though, its been a while since i really did anything like that.

whoever wrote this note is so extra and impractical; using metaphors and words like travesties in an encoded message is crazy work. my money is on Vein.

a bit of talk about how i went about analyzing it under the cut

i immediately clocked that it was a pigpen cipher cause its a very famous cipher (associated with several religious groups throughout history, but recently with the masons. heavily tied to secret societies), so i translated the first bit of it from pigpen to its typical corresponding latin alphabet letters, before realizing that wasnt working.

i briefly considered the idea that it was the traditional corresponding letters, but that it was just a different language, but what i was coming up with was clearly gibberish. i also considered the possibility that it wasn't going to be in english after it was properly deciphered, but i decided 1) it looks like english patterns of letters, 2) i dont know what else it would be. why would they write a message in Chinese in a cipher that translates specifically to the latin alphabet? 3) its the only language im familiar enough to crack and i want to have fun

then i went through the message highlighting repeated two and three letter words, as well as the singular one letter word. after figuring out with some educated guesswork and inferences what those were, i filled those letters in the rest of the message.

from there i looked for words that could only (reasonably) be one thing, and filled in the letters that werent already there, rinse and repeat until i was guessing at full words. then i noticed that the bottom row of the dotted three-box section of the cipher (the one that usually represents P, Q, and R) represented L, M, N. this made me realize that it was likely a shift of the letters from their normal location, something i had already suspected, but i figured frequency analysis would be the quicker way just incase that wasn't the case.

from there it was short work to fill in the rest of the alphabet and then to decipher the message

i'll admit that it took quite a bit longer than it should have, which is perhaps a bit embarrassing, but i'm quite rusty, and i was never more than a beginner in my "prime", so i think i did all right.

i don't know if they added the 4 shift as an attempt to "layer" a caesar with a pigpen, or as a fully knowledgeable attempt to make it just that much more difficult to read. a cipher like a pigpen--very common, with distinctive, non-letter symbols--is basically one of the only substitution ciphers this would have worked with, otherwise you've just created a different substitution cipher.

[barrieescaperoom]

From Novice to Expert: Navigating Escape Room Puzzles

Escape rooms are more than just a fun activity—they’re an exciting challenge for your mind. At the heart of every escape game are the puzzles: clever, creative, and sometimes downright tricky. Whether you’re a beginner or a seasoned solver, understanding how to tackle escape room puzzles can mean the difference between escaping in time or falling just short.

In this guide, we’ll break down the types of puzzles you’re likely to encounter, offer strategies to solve them, and help you level up from novice to expert.

What Are Escape Room Puzzles?

Escape room puzzles are mental and physical challenges placed throughout themed rooms. Players must solve these puzzles to unlock doors, discover clues, and ultimately escape before the clock runs out—usually within 60 minutes. These puzzles are designed to test your logic, observation, teamwork, and sometimes even your dexterity.

The fun lies in their variety, complexity, and the sense of accomplishment when everything clicks into place.

Common Types of Escape Room Puzzles

Understanding the different categories of escape room puzzles is key to solving them efficiently:

🔐 1. Locks and Keys

Classic puzzles involve physical locks—number combinations, keys, or letter codes. Clues to these combinations are hidden in riddles, objects, or around the room.

🧩 2. Pattern Recognition

Spotting recurring symbols, colors, or sequences often reveals critical solutions. These puzzles reward keen observation and attention to detail.

🕵️ 3. Hidden Objects

Some puzzles require you to search the room thoroughly for hidden items—magnets, notes, puzzle pieces, or blacklight-revealed messages.

💡 4. Logic and Deduction

These involve traditional logic puzzles, sequencing, or problem-solving steps. You might need to connect information from multiple sources to find the answer.

���� 5. Physical Tasks

Not all escape room puzzles are mental. Some require assembling parts, navigating mazes, or triggering hidden mechanisms.

📜 6. Ciphers and Codes

These include Morse code, substitution ciphers, or encrypted messages. A cipher key or chart is often needed to decode the message.

Tips for Solving Escape Room Puzzles Like a Pro

✅ Communicate Constantly

Share discoveries with your team. Often, a clue you found pairs with something someone else saw.

✅ Stay Organized

Designate a spot for solved and unsolved items. This keeps you from wasting time rechecking clues.

✅ Don’t Overthink

Many escape room puzzles are designed to be solved quickly once you understand their logic. If you're stuck, take a step back.

✅ Use Hints Strategically

Most rooms offer a set number of hints. Don’t be afraid to use them if you're truly stuck—they’re there to enhance the experience.

✅ Search Everything

Check drawers, books, under rugs, behind pictures—creators love hiding clues in plain sight.

How to Level Up Your Puzzle Skills

Play Different Themes – Each escape room style offers new puzzle types and skills to develop.

Practice Logic Games – Crosswords, Sudoku, and brain teasers keep your mind sharp.

Switch Roles – Try leading your group one game, then supporting the next—you’ll gain new perspectives.

Learn Basic Ciphers – Knowing Morse code or Caesar ciphers in advance can speed up decoding.

Watch for Meta-Puzzles – Some rooms feature puzzles that require combining multiple smaller ones.

Final Thoughts

Navigating escape room puzzles is a journey—from fumbling through your first lock to leading your team through the final door with seconds to spare. With the right mindset and strategy, each room becomes more than just a challenge—it becomes an adventure of creativity, communication, and connection.

So whether you're just starting out or aiming to become an escape room champion, keep your eyes open, your team close, and your mind sharp. Every puzzle solved brings you closer to victory—and a whole lot of fun.

[craftingtableus]

Nebula Codex: Unlock the Secrets of Sci-Fi Programming

In the world of sci-fi, where imagination takes us to far-off galaxies and futuristic technologies, there's an exciting way to combine these stories with learning real-world skills: programming. Imagine using a Sci-Fi themed coding kit to build your own gadgets and learn to code while being immersed in a science fiction adventure. This article explores how the Nebula Codex can help unlock the secrets of programming through fun, space-themed challenges.

How Sci-Fi and Programming Go Hand in Hand

Science fiction has always been a great source of inspiration. Many of the things we use today, like smartphones and AI assistants, were first dreamed up in sci-fi stories. By combining these imaginative ideas with coding lessons, we make learning programming more interesting and relatable.

What Are Sci-Fi Themed Coding Kits?

Sci-Fi themed coding kits are special educational tools that use popular science fiction stories and characters to teach coding. These kits allow users to create their own gadgets, robots, or games while learning programming skills. It's like turning yourself into a character in your favorite sci-fi story as you build cool tech with your code.

Example 1: Kano Star Wars The Force™ Coding Kit

One well-known kit is the Kano Star Wars The Force™ Coding Kit. With this kit, you can build a motion-sensing device that lets you control things with your hand, just like using a lightsaber. While working through fun challenges, you'll learn about programming concepts like loops, logic, and variables—all while interacting with characters from Star Wars like R2-D2 and BB-8.

Example 2: BBC Doctor Who HiFive Inventor Coding Kit

Another fun example is the BBC Doctor Who HiFive Inventor Coding Kit. This kit helps beginners get started with coding by using a mini-computer and lessons narrated by Jodie Whittaker, the 13th Doctor. You’ll learn how to use coding blocks and even create your own projects while exploring the world of Doctor Who.

Why Sci-Fi Themed Kits Are Great for Learning

Sci-Fi themed coding kits offer several benefits that can make learning to code easier and more enjoyable:

Keeps You Engaged: Learning programming becomes more fun when you get to interact with your favorite sci-fi characters and stories.

Practical Learning: Sci-Fi stories give real-life examples of how coding works, making complex ideas easier to understand.

Boosts Creativity: Designing and coding your own projects inspired by sci-fi allows you to think outside the box and come up with new ideas.

Your Sci-Fi Coding Adventure: The Nebula Codex

Let’s imagine you’re part of an adventure called the Nebula Codex, where you have to solve coding challenges to uncover the secrets of an alien civilization. Here’s how the journey might go:

Chapter 1: The Mysterious Signal

You pick up a strange signal from the Andromeda galaxy. To decode it, you need to understand binary code.

Coding Challenge: Create a program that converts text into binary code and back.

What You Learn: You’ll get to understand how data is represented in computers and learn basic programming.

Chapter 2: Unlocking the Quantum Gateway

The signal leads you to a quantum gateway that requires a password. The gateway uses a simple encryption system.

Coding Challenge: Write a program to encrypt and decrypt messages using a Caesar cipher.

What You Learn: You’ll explore basic encryption techniques and how coding can keep information secure.

Chapter 3: Communicating with the AI

After passing the gateway, you find an AI that can help you. But first, you must program the AI to understand your commands.

Coding Challenge: Create a chatbot that answers questions based on pre-written responses.

What You Learn: You’ll get an introduction to artificial intelligence and how it interacts with users.

Chapter 4: Navigating with a Holographic Map

Next, you need a 3D map to navigate the alien planet, but you’ll have to build it yourself!

Coding Challenge: Use a graphics library to create a 3D map that updates based on user input.

What You Learn: You’ll get hands-on experience with creating graphics and user interfaces.

Chapter 5: Solving the Final Code

In the last chapter, you discover the Nebula Codex, an ancient programming language that controls the alien planet’s technology.

Coding Challenge: Translate the instructions from the Nebula Codex language into working code.

What You Learn: You’ll put everything together and apply all the programming skills you’ve learned.

Choosing the Right Sci-Fi Themed Coding Kit

When picking a Sci-Fi themed coding kit, here are some things to consider:

Age and Skill Level: Make sure the kit is suitable for your age and programming experience.

Learning Goals: Think about which programming skills you want to focus on—whether it's basic coding, AI, or graphics.

Interactivity: Choose kits that let you build and see the results in real time, so you get hands-on experience.

Community Support: Look for kits with strong online communities where you can get help and share your projects.

Conclusion

The Nebula Codex is a perfect example of how combining sci-fi stories with programming can make learning fun and engaging. With a Sci-Fi themed coding kit, you can embark on an exciting adventure while mastering important coding skills. Whether you're building a lightsaber controller or creating a futuristic AI, these kits help unlock the mysteries of programming in a way that’s both educational and enjoyable. So, are you ready to start your journey into the world of sci-fi programming?

[13tinysocks]

Maam if this is beginner what am I

ZI’ll help ya out. It’s a cipher, Caesar. A caesar cipher is when the alphabet is moved X amount of spaces to the right or left. There’s variation but that’s the most commonly used. Most ciphers are to the right.

 The normal alphabet is your plain text: ABC and onwards. For simplicity sake, let’s say we have a shift of one. Your cipher text for ABC would end up being: ZAB. Since the entire alphabet has moved over one space, if you know how many spaces the alphabet has been moved you can figure out what the cipher text is saying. 

For a better and very short exp, look here: https://www.youtube.com/watch?v=o6TPx1Co_wg

It’s going to be challenging but I’m also a begginer with ciphers/cryptology in general. As we go through more ciphers we’ll be learning and improving a new skill together and I just think that’s neat. And we get to show not tell that Brian’s special interest is cryptology * smirk emoji *

[mathematicool]

I was thinking of learning matlab before I go to uni do you have any suggestions on how to start?

Hey anon,

I’m not an expert in programming - in fact I’d still call myself pretty much a beginner, so take my advice with a pinch of salt. If you’re looking to learn MATLAB because you’ll be studying it at university, I personally don’t know if I’d recommend learning it ahead of time, just based on my experience. My university taught MATLAB from scratch, starting with basics, and I think that’s the best way to learn it (you’ll have teachers and peers to help you through the process).

Otherwise, if you do really want to learn MATLAB, install MATLAB and look up some free courses on Google. I don’t think Code Academy does a free MATLAB course, but after a quick Google, I can see Udemy has a course. I haven’t used Udemy, but I know CS Dojo on YouTube has used it in the past. In fact, his video ‘How to Learn to Code’ is probably far better than any advice I can give you.

After you’ve learnt the basic syntax and what they do, I think the most useful thing you can do is create something - like a game. I remember in my first year of uni, I had to fiddle with basic encryption and decryption using Caesar Cipher, and it was pretty fun using what knowledge I had to try to encrypt and decrypt messages. Since it was fun, I enjoyed using MATLAB and it made my experience learning it so much better.

Also, don’t get too bogged down about syntax. I think the most important skill for coding is being able to problem solve. For example, with Caesar Cipher, I had to think about how to actually get the encryption/decryption working e.g. using modulo arithmetic etc. If you’re good at maths, it helps.

My advice is pretty general and can be applied to any programming languages. That’s mostly because the difference between many languages at beginner level is just the syntax, really. You just need to make sure you’re good at problem solving. I really recommend watching the CS Dojo video that I mentioned, as he has the right experience to give this sort of advice!

Hope that helps.

All the best.

[sdferferedd]

(PDF) Download Cracking Codes with Python: A Beginner's Guide to Cryptography and Computer Programming by Al Sweigart

  Read/Download Visit :

https://happyextra12.blogspot.com/?book=1593278225

Book Details :

Author : Al Sweigart

Pages : 416 pages

Publisher : No Starch Press

Language : eng

ISBN-10 : 1593278225

ISBN-13 : 9781593278229

Book Synopsis :

Read Online and Download Cracking Codes with Python: A Beginner's Guide to Cryptography and Computer Programming .In Cracking Codes with Python, you'll learn how to program in Python while making and breaking ciphers, which are used to encrypt secret messages. (No programming experience required!). After a quick crash course in programming, you'll make, test, and hack classic cipher programs. You'll begin with simple programs like the Caesar cipher and then work your way up to public key cryptography and the RSA cipher, which is used for modern secure data transmissions. Each program comes with the full code and a line-by-line explanation of how things work. By book's end, you'll walk away with a solid foundation in Python and same crafty programs under your belt. Learn how to: -Combine loops, variables, and flow control statements into real working programs-Use dictionary files to instantly detect whether text is English or nonsense-Create programs to test that the code you've written is working correctly-Write your own programming modules that you can import and use in other programs-Debug .

Al Sweigart book Cracking Codes with Python: A Beginner's Guide to Cryptography and Computer Programming.

 sreading

[kaocandy]

Python for Beginner : Hack The Caesar Cipher ☞ http://learnstartup.net/p/H17CCTKlx- #python rkIsUbJxI

[secdino]

SA Wk 3: OTW Bandit

To start off the CTF journey, I came across OverTheWire (OTW) during the search for potential CTF websites in Wk 2. OTW Bandit is recommended  as the best place to start for absolute beginners by both themselves as well as other user blogs. While my main focus is likely to be on the Pwnables.kr website for Reverse Engineering, I decided (as with the proposed schedule in ‘Something Awesome Wk 2: Initial Proposal’) to test the waters and see how long it takes to do ‘beginner’ CTFs.

Having set up my VM a few days ago (in a previous post), I decided to try and get through as much of Bandit as possible in roughly 2.5 hrs (stop after 2.5 hrs and see how far I managed to progress). The following summarises my progress:

Level 0: A simple level to test our ability to SSH into the remote server and to simple ‘cat readme’, in which the flag for this ultra-beginner level was stored.

Flag: boJ9jbbUNNfktd78OOpsqOltutMc3MY1

Level 1: The flag was stored in a file named ‘-’. Simply doing ‘cat -’ got nowhere, but ‘cat ./-’ yielded results.

Flag: CV1DtqXWVFXTvM2F0k09SHz0YwRINYA9

Level 2: This filename for the flag file this time was ‘spaces in this filename’. It was probably aimed at getting beginners to learn ‘\’ as an escape key, i.e. ‘cat spaces\ in\ this\ filename’. I was a bit too lazy for that and went with ‘cat spa[tab]’ to token match the rest of the name. :)

Flag: UmHadQclWmgdLOKQ3YNgjWxGoRMb5luK

Level 3: Still not really being challenged yet, we’re about 15 minutes in (simply cos the SSH takes a while to run in VM) and this level was a combination of ‘cd inhere’ and ‘ls -a’ to find the hidden flag file.

Flag: pIwrPrtPN36QITSp3EQaw936yaFoFgAB

Level 4: Somewhat annoying, 10 files to choose from and the flag is in the only human-readable one. I did a linear search by ‘cat’-ing each file to see which did NOT produce a binary spam. Of course it had to be the 3rd last file (file07) and not near the beginning...

Flag: koReBOKuIDDepwhWk7jZC0RTdopnAYKh

Level 5: In this level there were multiple directories with multiple files in each one of which 1 was the flag file. We were given some conditions which the flag file satisfied such as its size and not being executable. From this exercise I learnt to use the ‘find’ command line function to locate the answer.

Flag: DXjZPULLxYr17uwoI01bNLQbtFemEgo7

Level 6: This was similar to Level 5 with only a variation in the location in which to ‘find’ and some conditions. The search was conducted on the entire server, ‘/’ and by user and owner: ‘find / -size 33c -user bandit7 -group bandit6’.

Flag: HKBPTKQnIay4Fw76bEy8PVxKEDQRKTzs

Level 7: I’d heard of the ‘grep’ command before but i’d never actually tried or been able to use it properly. Not anymore!! The flag being stored next to “millionth” in a data file was clearly calling for ‘cat data.txt | grep “millionth” ‘ to be used.

Flag: cvX2JJa4CFALtqS87jk27qwqGhBM9plV

Level 8: I really had no idea how to do this one at first but the flag being stored in the “only line of text that occurs only once” led me to search for command line functions which could look for distinct lines - ‘uniq’. After some man page reading on how to use the ‘uniq’ function, it turns out the input needed to be sorted, so that directed me to the ‘sort’ man page. Some more reading later, I arrived at ‘sort data.txt | uniq -u’.

Flag: UsvVyFSfZZWbi6wgC7dAFyFuR6jQQUhR

Level 9: From this task, I learnt about the ‘strings’ function, which prints the strings of human-readable characters from a file. This combined with some more ‘grep’-ing got us the flag: ‘strings data.txt | grep “=“ ‘.

Flag: truKLdjsbJ5g7yyJ2X2R0o3a5HQJFuLk

Level 10: Another new function to learn...the flag was in a file containing base64 encoded data. Fortunately, there’s a ‘base64′ function in command line which is able to convert it back to regular ASCII with the decode flag, ‘base64 --decode data.txt’.

Flag: IFukwKGsFW8MOq3IRFqrxE1hxTNEbUPR

Level 11: The alphabetical text in the flag file for this level was ‘encrypted’ or rather translated by 13 positions - a very straightforward caesar cipher. In order to avoid deciphering it manually, I read into the ‘tr’ command, which allows a user to translate text by providing a mapping. It took longer than I expected to learn how to input the arguments, but it worked out in the end as ‘cat data.txt | tr ‘[A-Za-z]’ ‘[N-ZA-Mn-za-m]’ ‘.

Flag: 5Te8Y4drgCRfCx8ugdwuEX8KFC6k2EUu

Level 12: The file provided was a hexdump of the flag file which had also been repeatedly compressed in different ways. Man pages were especially useful in learning how to use ‘xxd’, as a first step to convert the hexdump back to a binary file. Afterwards, I familiarised with the ‘file’ command, which tells a user the format of a file’s contents. What followed was what seemed like an endless repetition of ‘bzip’, ‘gzip’, and ‘tar’ commands to decompress and convert the formats of the file. At one point I accidentally forgot to change the file name to match the correct format and was unable to reverse the problem by the time I found out, meaning I had to start it again. :c Eventually, the ‘file’ command returned ASCII, meaning I was able to ‘cat’ the flag out.

Flag: 8ZjyCRiBWFYkneahHwxCv3wb2a1ORpYL

And that was about how far I was able to get in a little over 2 hours. I honestly thought after the first 3-4 levels that I’d be able to almost finish, but the last few levels I completed took much longer than expected - reading man pages and learning to use new functions takes some time apparently.

From today’s exercises alone, I’ve learnt how to use about 10 new command line functions, as well as gotten a good feel of what CTFs are like. With the timing, I’m unsure of whether I’ll be able to complete the proposed 5-6 CTFs a week given these 12-13 beginner levels took a full 2 hours. Hopefully I will get better as I go. For now, the next step is to try out the Pwnables.kr website!

[thetopprogrammer]

Python for Beginner Python for Beginner by Hack Caesar Cipher What you’ll find out The Caesar cipher, among one of the most popular cipher in background Python from starting with: if, for, string, feature. All necessary expertise in order to hack Caesar cipher Python programs to secure message usage Caesar cipher policy Python programs to […]

[rafi1228]

The bare bones of programming without the bling!

What you’ll learn

use the fundamental threshold concepts underlying all programming languages to write C# programs.

take their knowledge of C# and adapt it in a variety of settings that use C# such as robotics, Unity, Visual Studio and Unreal.

transition from C# to using other programming languages with ease.

Requirements

You should be able to use a Windows or Mac machine at a beginner level.

Description

This course will not teach you to become a programmer.  Programming is like martial arts, it takes years and years of practice.  No course can make you a grand master no matter what it promises.  What this course WILL do is give you a solid foundation in programming as a skill for life using C# as the vehicle. You will learn about the fundamental nature of the computer and how to communicate with it through the development of programs to perform a variety of tasks and solve numerous problems.  Following the same curriculum used to teach 1st year computer science in university in the first 6 months of a degree, you will learn not just what to program but 1) why it is is done like that and 2) how you can broaden your skill set in programming beyond this single course.

The topics covered include:

Bits, Bytes and Binary;

Management and Manipulating Memory;

Performing Mathematical Operations;

Designing Dynamic Program Execution with Logic;

Developing Repetition for Fast Data Processing;

Handling User Input; and,

Reading and Writing to Files

The course material has been developed for students using either Windows or Mac computers using the freely available Mono C# compiler.  It is well paced covering each concept in bite sized chunks and filled with hands-on workshops that will build projects across a variety of domains.  Some of the programs that will be written include:

a Caesar Cipher for encrypting text;

a Hangman Game;

a Number Guessing Game;

a Chatterbot;

storing and retrieving names and addresses in a file; and

reading and processing text from a webpage.

At the end of this course you will be equipped with a toolbox of skills that you can apply in your job and day-to-day life making you more employable and relevant in today’s marketplace.

What students are saying about this course:

Penny is a really good teacher, this is the kind of C# class I’ve been looking for and it is just right for what I need right now. I would highly recommend it.

This course has been awesome. I knew virtually nothing about coding, and now I’m halfway thru, loving it, and learning a TON! Great teacher, clear and concise lessons with plenty of opportunity to learn, test code, experiment, and consistent quizzes and challenges. 5/5

I’m an artist, code was always something that I had the desire to learn but at same time I always thought it was something too complex and boring, until I decide to buy this course and start watching these videos. Everything is very well explained, she teaches really well, straight to the point. Now I’m finding it extremely fun to learn and I’ve been doing the course and watching the videos as if it were a Netflix series. I get excited at every new thing that pops up 😀 I also love when you have to do challenges, it’s like a game, super fun. It is very easy to follow, even if you have zero knowledge in coding, like me when I started. Recommended!

Who this course is for:

Everyone that wants to code and thoroughly understand what they are typing into the computer.

Created by Penny de Byl, Penny de_Byl Last updated 12/2018 English English [Auto-generated]

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The post Naked C#: A Beginner’s Guide to Coding appeared first on Free Course Lab.

[pythonproz]

Python for Beginner : Hack The Caesar Cipher ☞ https://t.co/lDMZY4HajA #python nwV5jWFznkl https://t.co/SfQ70wuY6V

[pythonfan-blog]

Python for Beginner : Hack The Caesar Cipher ☞ http://on.learn4startup.com/rk6L3zbKX #python

[5162051]

Something Awesome | Reflection

Sooo, I’ve completed the tasks that I set out to do and in the process, learnt a lot about different ciphers and encryption methods. From Caesar Ciphers to RSA Keys, the process of coding them up in Python really forced me to have an in-depth and solid understanding of all these concepts. 

Caesar Ciphers were a good introduction into the whole cipher world, because it’s a perfect beginner cipher. Incredibly easy to understand while still maintaining a little difficulty in the whole coding process. The special thing about coding a Caesar Cipher was understanding how computers interpret characters. Because the easiest way to do this was to convert characters to their ASCII values and perform the shift. 

Transposition Ciphers were a lot harder than Caesar was. The concept was easy enough to understand but thinking about within the framework of coding logic was challenging to get my head around. However because of the fact I had to get used to the whole logic of coding something like this, and using columns to create the message, it helped me understood the process of creating a transposition cipher. 

Vignere Ciphers, once the understanding is reached and how it really is just a lot of different Caesar Ciphers mapped to a key word, it became pretty much the same process as a Caesar Cipher. Except this time around, since the key was not in the form of a number, a discovered a quick hack to this way finding the index of that letter in the alphabet to shift. I now have a much better understanding of Vignere Ciphers and its operation. 

For RSA Keys, I believe it was a good thing to finish on. The whole process and rules for RSA are so complex and intricate that it really proves to be a much more challenging and interesting project to work on. Because I had to implement this in code, I really had to study up on a lot of the mathematical properties in RSA. Modulus being a big part, and factorising another. I found it very interesting to note, as this one was different to the other ones being that, this is still used in modern day encryption methods. So to know how it maintains that was very interesting.

Overall, I completed all 4 ciphers I was planning to code, each with decoding tools. Other than that, for each cipher I created a substantial report detailing the history and uses and implementation of each one with a compiled blog report of the entire coding process.