Deterministic Public-Key Encryption Revisited
One of the maxims of modern cryptography is that "Randomness is needed for good encryption," meaning the encryption algorithm of a scheme that should be randomized. Such an encryption scheme is called probabilistic. Indeed, probabilistic encryption is necessary to meet the fundamental notion of semantic security introduced by Goldwasser and Micali. An interesting question, however, is whether the authors can instead leverage message entropy to achieve security, rather than requiring the encryption to be probabilistic.