09.11.2015 16:49, Jim Starkey wrote: > For CBC mode, the initialization vector is XORed into the first block of > plaintext. Without this (or something like it), the first 16 bytes of > every page would have the same encryption, allowing a mapping from > cryptotext to presumed plaintext, possibly leaking useful information.
XORing of two known values (or doing whatever similar) won't add more problem for attacker because the result also will be a known plaintext. To make plaintext unknown, initialization vector also must be unknown. But all this doesn't matter as AES is considered to be practically invulnerable to known-plaintext attacks. -- WBR, SD. ------------------------------------------------------------------------------ Presto, an open source distributed SQL query engine for big data, initially developed by Facebook, enables you to easily query your data on Hadoop in a more interactive manner. Teradata is also now providing full enterprise support for Presto. Download a free open source copy now. http://pubads.g.doubleclick.net/gampad/clk?id=250295911&iu=/4140 Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
