Dan Boneh from Stanford University offers a free online cryptography course with lectures covering topics such as stream ciphers, block ciphers, message integrity, authenticated encryption, key exchange, public-key encryption, and digital signatures. The course includes a free textbook authored by Boneh and Shoup, providing in-depth explanations, security proofs, and exercises. Controversial information may arise regarding the discussion of attacks on various encryption methods. Noteworthy content includes a crash course in discrete probability, real-world examples of stream ciphers, and various constructions for encryption methods. Students can access slides, videos, and a syllabus for each week’s lectures.
https://crypto.stanford.edu/~dabo/courses/OnlineCrypto/