3 ms·
Yeah, they've got that covered too. The second paragraph of the paper says that they're working with the notion of "deniable encryption" introduced in a paper b
by theoh 8y ago
Yeah, they've got that covered too. The second paragraph of the paper says that they're working with the notion of "deniable encryption" introduced in a paper by Canetti et al: http://www.wisdom.weizmann.ac.il/~naor/PAPERS/deniable.pdf http://www.wisdom.weizmann.ac.il/~naor/PAPERS/deniable.pdf
Here's the abstract of the Canetti paper:
"Consider a situation in which the transmission of encrypted
messages is intercepted by an adversary who can later ask the sender to
reveal the random choices (and also the secret key, if one exists) used in
generating the ciphertext, thereby exposing the cleartext. An encryption
scheme is deniable if the sender can generate ‘fake random choices’ that
will make the ciphertext ‘look like’ an encryption of a different cleartext,
thus keeping the real cleartext private. Analogous requirements can be
formulated with respect to attacking the receiver and with respect to
attacking both parties.
Deniable encryption has several applications: It can be incorporated in
current protocols for incoercible (“receipt-free”) voting, in a way that
eliminates the need for physically secure communication channels. It
also underlies recent protocols for general incoercible multiparty computation (with no physical security assumptions). Deniable encryption
also provides a simplified and elegant construction of an adaptively secure
multiparty protocol.
In this paper we introduce and define deniable encryption and propose
constructions of such schemes. Our constructions, while demonstrating
that deniability is obtainable in principle, achieve only a limited level of
it. Whether they can be improved is an interesting open problem."
I'm not sure how the paper under discussion relates to those applications, if at all.
I'm not sure I buy the argument you appear to be making that a single principal can use a fake OTP to achieve deniability with any encryption scheme, but that this breaks down when both sender and receiver are coerced. If the fake plaintexts don't match it comes down to one person's word against another. The consequences of that scenario are outside the scope of "deniable encryption". It sounds a bit like a prisoner's dilemma situation.
But the key defining feature of "deniable encryption" is of deniability within a specified encryption scheme.