Visualizing the poor randomness of RND() on the Commodore 64 and 128 compared to the PET and Plus/4. Clear patterns emerge when you plot the output.

Generating pseudo-random numbers with the Lagged Fibonacci Sequence on the VIC-20. Building reusable BASIC subroutines for the cipher toolbox.

Implementing Pontifex/Solitaire—the playing card cipher from Cryptonomicon designed by Bruce Schneier—on the Commodore 64.

Generating one-time pads on a Commodore 64. Probably a bad idea for real security, but it looks cool.

Understanding hash collisions by finding them in a simple checksum from a 1984 type-in game. Demonstrating why weak hashes fail.

Finding prime numbers on the Commodore 64 for cryptographic purposes. A practical introduction to primes and primality testing.

Implementing the RC4 stream cipher on the Commodore 64, exploring the algorithm that powered WEP, WPA, and many other encryption protocols.

Exploring pseudo-random number generation on the Commodore 64 using Linear Congruential Generators, a key building block for cryptographic applications.

Understanding the XOR operation and its magical properties for data recovery in cryptography and disk storage on the Commodore 64.

A quick tutorial on determining string length in 6510 assembly language, comparing the approach to Python’s simple len() function.

Recreating the WarGames movie launch code sequence on the Commodore 64, implementing brute-force hash table searching in assembly.

Recreating the Terminator 2 ATM PIN cracker scene on the Commodore 64, using SID chip random numbers and 6502 assembly.

Building a Caesar cipher encoder and brute-force decoder on the Commodore 64, demonstrating how to crack simple substitution ciphers programmatically.

Implementing the shift cipher on the Commodore 64, encoding messages by rotating alphabet positions similar to a physical code wheel.

Starting a series on implementing ciphers in Commodore assembly language, beginning with a simple string reversal as the first building block.

Implementing a one-time pad cipher by hand using dice-generated random numbers, inspired by the encryption methods in Cryptonomicon.