Re: [STDS-P1619] Does XTS provide protection against watermarking?.

[Cyril Guyot <Cyril.Guyot@xxxxxxxxxxxxxx>]

Hi Garry,

For simplicity, let's assume that the XTS "block" size is a multiple of the
block size of the underlying block cipher such that we do not have to deal
with ciphertext stealing.
Then such a watermarking attack would be a chosen plaintext attack on the
indistinguishability of XTS from a perfect tweakable random permutation.
This would contradict the indistinguishability property of XTS under chosen
ciphertext attack proven in section 3.3) of
http://csrc.nist.gov/groups/ST/toolkit/BCM/documents/comments/XTS/XTS_comments-Liskov_Minematsu.pdf

Best regards,
Cyril


                                                                           
             Garry Mccracken                                               
             <Garry.Mccracken@                                             
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                                       [STDS-P1619] Does XTS provide       
             Please respond to         protection against watermarking?.   
              Garry Mccracken                                              
             <Garry.Mccracken@                                             
               WINMAGIC.COM>                                               
                                                                           
                                                                           
                                                                           




Hi, does XTS provide protection against watermarking
(http://en.wikipedia.org/wiki/Watermarking_attack )?

http://en.wikipedia.org/wiki/Disk_encryption_theory
  mentions watermarking under CBC but doesn't say XTS protects against
watermarking.

Does XTS provide any protection against watermarking?

Garry