The notion of plaintext-awareness is well-known for asymmetric encryption, but the notion seems to make sense for symmetric encryption as well. Is this a known concept?

  • $\begingroup$ What research have you done? I’m asking because we expect you to do a significant amount of research before asking here, including searching this site for related Q&As that might shed light on your question. At worst it will help you frame a better question; at best it’ll answer it… $\endgroup$ – e-sushi Sep 21 '14 at 14:44
  • $\begingroup$ @e-sushi: I've read some papers on plaintext awareness (Bellare and Pallacio, Birkett and Dent); I've done a Google Scholar search for "plaintext-awareness" "symmetric encryption" and didn't see anything relevant; I've searched here for plaintext-awareness. $\endgroup$ – Max Sep 21 '14 at 16:05
  • $\begingroup$ I assume any authenticated cipher is plaintext aware if you consider the tag part of the resulting ciphertext. Actually, as you would also require the key, it would probably be much stronger than that, so maybe this is why it isn't much talked about (?) $\endgroup$ – Maarten Bodewes Sep 21 '14 at 16:24
  • $\begingroup$ @owlstead: thanks! I was looking at a variant of plaintext-awareness which handles the key a little differently. I failed to notice that this difference was completely essential in the private-key case. $\endgroup$ – Max Sep 24 '14 at 9:41
  • $\begingroup$ Of course block ciphers and most block cipher modes of encryption (without authentication) do not have plaintext awareness - but I guess that the fact that PRP's don't have plaintext awareness is -eh- kind of obvious. $\endgroup$ – Maarten Bodewes Sep 24 '14 at 15:19

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