Re: How long to trust 3DES

Francois Grieu wrote:
The threat of full decryption, equivalent to key recovery,
seems remote, but I would not say null given the timeframe.

A much more sizable threat is partial decryption, especially if
the same key is reused over multiple files and some portion of
the files is known to the attacker, because 3DES only has
a 64-bit block size.

In my application (digital video) discovery of a block or two of
plaintext is not a major concern. Discovery of the key or of a
significant viewable segment of the plaintext must be prevented. Our
application uses a separate (3-key) 3DES key + IV for each file, and
are using CBC mode.

.

Relevant Pages

  • Re: How long to trust 3DES
    ... A much more sizable threat is partial decryption, ... In my application discovery of a block or two of ... significant viewable segment of the plaintext must be prevented. ...
    (sci.crypt)
  • Re: How long to trust 3DES
    ... Alan wrote: ... Discovery of the key or of a ... significant viewable segment of the plaintext must be prevented. ...
    (sci.crypt)