Install cifer by entering the following commands in the terminal:
sudo apt update sudo apt install cifer
Description:
multipurpose classical cryptanalysis and code-breaking tool
Cifer provides many functions designed to aid in cracking classical ciphers; a group of ciphers used historically, but which have now fallen into disuse because of their suceptability to ciphertext-only attacks. In general, they were designed and implemented by hand, and operate on an alphabet of letters (such as [A-Z]). . It operates using text files as input and output, and can perform both brute force and other, more sophisticated, attacks against many classic encryption schemes. In addition, it provides many utilities such as frequency analysis and automated encryption/decryption of texts.
Homepage: http://code.google.com/p/cifer/
Version: 1.2.0-0ubuntu4
Section: universe/misc