False-Bottom Encryption: Deniable Encryption from Secret Sharing

Homomorphic Secret Sharing from Paillier Encryption

A recent breakthrough by Boyle et al. [7] demonstrated secure function evaluation protocols for branching programs, where the communication complexity is sublinear in the size of the circuit (indeed just linear in the size of the inputs, and polynomial in the security parameter). Their result is based on the Decisional Diffie-Hellman assumption (DDH), using (variants of) the ElGamal cryptosyste...

Deniable Encryption

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 encr...

Practical Deniable Encryption

Stream Deniable-Encryption Algorithms

A method for stream deniable encryption of secret message is proposed, which is computationally indistinguishable from the probabilistic encryption of some fake message. The method uses generation of two key streams with some secure block cipher. One of the key streams is generated depending on the secret key and the other one is generated depending on the fake key. The key streams are mixed wi...

Separating Sources for Encryption and Secret Sharing

Most cryptographic primitives such as encryption, authentication or secret sharing require randomness. Usually one assumes that perfect randomness is available, but those primitives might also be realized under weaker assumptions. In this work we continue the study of building secure cryptographic primitives from imperfect random sources initiated by Dodis and Spencer (FOCS’02). Their main resu...