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Java crypto Cipher-Block-Chaining isn't chaining
Here a question for a cryptography specialist.
I just found out that the Java JCE (java Cryto Extension API) as it is
designed by Sun and implemented by many others, that its
Cipher-Block-Chaining code (for DES, DESede, idea, etc.) is not doing
any chaining between blocks of data. That is, the IV that carries the
cipher end state of previous encrypted block of data to the next one,
stays the same from block to block. It is only randomly determined
upon cipher initialization, and there is a way to set and to get it.
The IV is however not changed when encrypting data.
To me this defeats the purpose of Cipher-Block-Chaining, which
guarantees that each block (exchange) of encrypted data depends on the
previous one.
But what do you crypto specialists think about this?
--
Robert Luursema R.Luursema@incaa.nl Incaa Datacom b.v.
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