Symmetric Cryptography by University of Colorado (Coursera)

Symmetric cryptography uses a shared secret key to secure message secrecy, making it impossible for unauthorized attackers to read it. When the message is encoded in natural language such as English, the course covers substitution and transposition techniques, which were the foundations for traditional encryption. After that, they describe current block ciphers and examine the frequently used cipher algorithms in DES, 3-DES, and AES, building on product ciphers (using both substitution and transposition/permutation). Finally, they introduce alternative modes of block cipher operations in ECB, CBC, CFB, OFB, and CTR modes to enable the usage of block ciphers to handle changing data length.

This course is part of both the Applied Cryptography specialization and the Introduction to Applied Cryptography specialization, and is cross-listed. The course is well-designed and will be of great use to all cryptographers. The lectures are very informative and easy to follow. However, non-computer scientists may find the DES pseudo code assignment challenging.

Duration: 13 hours

Rating: 4.5 out of 5

Link: coursera.org/learn/symmetric-crypto