Dr. Soper discusses encryption concepts. Topics covered include encryption algorithms, keyed and keyless cryptosystems, cryptanalysis, breaking encrypted messages, substitution, transposition, and product ciphers, the Caesar cipher, the Vigenère cipher, one-time pads, the Vernam cipher, book ciphers, symmetric and asymmetric cryptosystems, public-key encryption, stream ciphers, block ciphers, the data encryption standard (DES), and the advanced encryption standard (AES).