This page con­tains var­i­ous unstruc­tured notes about cryp­to relat­ed things. General notes If you find some­where that some­thing should be ran­dom, but it isn’t, this is already an impor­tant finding. Stream Ciphers A stream cipher encrypts a clear­t­ext bit for bit or char­ac­ter for char­ac­ter (nor­mal­ly via XOR) with a secret key. It pro­duces a…