This document describes an application called "ENDECS" that provides data compression and encryption using an iterative technique. The application uses fewer bits to represent characters in a file by assigning a unique code to each distinct character. This allows the file size to be reduced by up to 50%. The encryption process maps the characters to codes based on an encryption key file. Decryption reverses this process to reconstruct the original file. The application was developed in C using the VIM text editor and GCC compiler, and can be debugged with GDB. It provides a command line interface to compress, encrypt and decrypt files.