xagawa
Reputation
1,473
Next privilege 2,000 Rep.
 Apr 27 awarded Enlightened Apr 27 awarded Nice Answer Apr 21 awarded Yearling Nov 19 comment Stern identification scheme to signature scheme You are right but overlooked that the challenge should be unpredictable enough. We should make the Stern protocol pallalel, say 64 times, and then convert it to signature as you wrote. May 24 reviewed Approve Elliptic Curve Cryptography Encryption and text representation implementation May 24 reviewed Approve Alternative to NSA encryption algorithm Apr 21 awarded Yearling Apr 17 revised Given a message and signature, find a public key that makes the signature valid (ECDSA) (s_1,k_1) -> (s_1,r_1) as @Ruggero pointed out. Describe the attack. Apr 17 comment Given a message and signature, find a public key that makes the signature valid (ECDSA) Thank you for pointing out my mistake. Well, I correct the form of the signature. But, please notice that the attack I described does not require knowledge of $k_1$. Apr 6 comment Pseudorandom Function Proof what happens if I query x=011...1 to your second candidate? Feb 24 revised Randomness re-use in LWE encryption scheme Correct minor typo Feb 24 comment Randomness re-use in LWE encryption scheme I'm sorry that I omit the details. I used the generalized leftover hash lemma, instead of the leftover hash lemma. Since $rb$ leaks $\log{q}$-bit information of $r$, I set $m \geq (n+2) \log q\ \ldots$ instead of $m \geq (n+1) \log q\ \ldots$. I'll add more explanations. Feb 23 answered Randomness re-use in LWE encryption scheme Feb 23 comment Zero Knowledge Non Interactive Proof with random oracle Hint: Notice that the simulator can program the random oracle and the original protocol is honest-verifier ZK. Dec 5 awarded Revival Sep 30 awarded Explainer Aug 20 reviewed Approve S-box with differential uniformity = 2 Aug 4 comment Public key in fully homomorphic encryption over the integers What happens if you set it even? Jul 24 comment Universal hashing techniques based on matrix multiplication Proving \epsilon-universality of random matrix hashing sounds an execise. I once found proofs in Shoup's textbook. Jun 8 reviewed Approve Why are there only positive value points on an elliptic curve?