Reverse Engineering a 90s Hebrew-English Word Processor

This blog post details the process of reverse engineering QText, a DOS-era Hebrew-English word processor written in Turbo Pascal from the mid-90s, to decrypt its locked documents. The authors, facing a client's lost password, leveraged the simplicity of the encryption algorithm – the key was embedded within the file – and pursued both brute-force and reverse engineering approaches to reconstruct the key derivation algorithm. They successfully recreated the algorithm and developed a Python script for automated decryption. The case study offers insights into early software development cryptography and reverse engineering techniques, highlighting the evolution of information security.