Block Cipher Modes of Operation - Theory and Practice

Presenter: Jim Platania Abstract: "We all rely on block ciphers to safely transmit and store all kinds of information. These cipher algorithms (including AES) encrypt and decrypt fixed-size blocks of data, one by one; as such their designs abstract from any notions of block 'inter-relatedness'. But a perceivable inter-relatedness of encrypted blocks could betray the true shape of their contents, possibly rendering the encryption useless. This is where modes of operation intervene, on the multi-block level, either upholding or breaking the security of many blocks of data. We'll walk through four modes of operation, examining their origins, how they work, what they do best, and where they fall short."