There are many schemes that can advertise themselves with certain security notions, usually IND-CPA or IND-CCA2, for example plain ElGamal has IND-CPA security but doesn't provide IND-CCA security. ...
Is there a public key semantically secure cryptosystem for which one can prove in zero knowledge the equivalence of two plaintexts?
If Alice encrypts two messages $a$ and $b$, such that $x=E(a)$, $y=E(b)$. Can Alice prove (without revealing $a$, $b$ or the private key) that $a = b$? Obviously the proof must not be too long and it ...
I'm taking coursera cryptography course. The definition of semantic security is hard to understand. I tried to slightly restate it (the word "efficient" was in the original definition). Do I get it ...
Currently hearing a lecture on cryptography, and the professor gave us the definition of semantic security, which is roughly the following (formally not quite complete, but you get the idea): ...
The first question: what is the exact definition of semantically secure? Basically, a cryptosystem is semantically secure if given the public key and the ciphertext, an adversary cannot learn any ...
Let (E,D) be a secure block cipher. Consider the following tweakable block cipher: ...