On 11/9/2015 7:37 AM, Dimitry Sibiryakov wrote: > 08.11.2015 20:12, Jim Starkey wrote: >> Use the page number for the initialization vector. > It is also pointless.
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. A fundamental principle of cryptography is never encrypt predictable stuff the same way multiple times. Violation of this led to the cracking of both Enigma and WEP. It's very hard to obscure encryptions of various versions of the same page, but using the same initialization vector for every page is unnecessary and dumb. But perhaps you have a more clever idea of how to construct a per-page initialization vector? > ------------------------------------------------------------------------------ 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
