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 Yearling
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11h
comment How to generate encryption key for block cipher
Why would you use blowfish in 2015? 64 bit blocks limit the amount of data you can securely encrypt using a single key, so it's pretty annoying to use.
1d
comment Factorize RSA knowing several N and E
@Antimony While RSA moduli usually have two prime factors, that's not always the case. Using more factors improves the CRT speedup, but you need to be careful that the factors remain big enough so that elliptic curve factorization (whose cost depends on the size of the factors) is more expensive than GNFS (whose cost depends on the size of the modulus).
2d
comment point addition in NaCl/libsodium (Curve25519)
NaCl isn't an ECC library, it only offers higher level operations like key-exchange and signatures and doesn't have point addition in its public API. You should be able to find an edwards form point addition function in its Ed25519 implementation.
Jul
26
revised Show How to Efficiently Solve the Computational Diffie-Hellman Assumption given an Algorithm that Solves the Square-DH Problem
edited tags
Jul
26
comment Show How to Efficiently Solve the Computational Diffie-Hellman Assumption given an Algorithm that Solves the Square-DH Problem
Related problem: Can we reduce Diffie-Hellman problem to “Discrete-log inversion” problem?
Jul
26
answered Why is the whole initial state used in the final addition of Salsa20 and ChaCha?
Jul
24
revised Why is Rabin encryption equivalent to factoring?
edited tags
Jul
23
comment what is the best Encryption algorithm to encrypt real time voice
Unless you're using very low power hardware, performance shouldn't matter much since voice needs <10kB/s. I'd use UDP and encrypt each packed separately using authenticated encryption. AES-GCM and Salsa20Poly1305 are popular choices.
Jul
22
comment Question about the key in RC4
@lena What's your target hardware? The relative performance of ciphers varies a lot between different CPUs.
Jul
21
awarded  Yearling
Jul
20
revised Can I get the private key through the public key in RSA?
rolled back to a previous revision
Jul
19
comment Why don't use random padding in RSA?
AFAIK what Yehuda described is called RSA KEM. I believe it comes with a pretty strong security proof.
Jul
18
comment How is an epsilon of 1/1000 non-negligible?
1) This question is about what it means for an attacker's advantage to be negligible. Your answer doesn't address that at all. 2) Exploiting a weak PRNG to factor an RSA modulus generated by it isn't related to brute-force. 3) If you're referring to the "many moduli have a prime in common" problem, that was caused by very badly seeded PRNGs outputting identical data of several hundred bits for the first request of random data. This is unrelated to small biases.
Jul
18
comment Why does “2xAES-256” provide “99.99%” security strength whereas “1xAES-128” provides “40%”?
@mikeazo Should I trust CipherCloud? has been closed and deleted. While this question isn't as as non constructive, it still has the "I want to criticize that product but must do it disguised as a question" trait.
Jul
18
comment Why does “2xAES-256” provide “99.99%” security strength whereas “1xAES-128” provides “40%”?
I'm closing this because it's not a genuine question about cryptography. It's a post designed to make fun of ridiculous marketing claims, just phrased as a question. If you enjoy debunking bad crypto, you might want to create a blog, similar to Bruce Schneier's doghouse.
Jul
18
comment Deterministic ECDSA signatures?
@DrLecter The OP wants verifiably deterministic signatures and already linked that RFC.
Jul
17
revised Deterministic ECDSA signatures?
edited body
Jul
17
answered Deterministic ECDSA signatures?
Jul
15
reviewed Reviewed EAX cipher mode with nonce equal header
Jul
15
revised EAX cipher mode with nonce equal header
edited tags