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 Apr 16 comment Comparison of RSA and DRSA scheme using SageMath @PinkimaniGoswami: that's the current known limit, which implies that we can't gain that much from picking a fast $d$. It's typically assumed that it's safer to avoid special $d$'s entirely Apr 16 answered How to prove hardness of approximate-GCD problem? Apr 15 comment Comparison of RSA and DRSA scheme using SageMath @PinkimaniGoswami: other than multiprime RSA (where the modulus is a product of more than 2 primes; you have to be careful with that), there isn't a good way to make RSA (or DRSA) go faster. Selecting a small $d$ value makes it easier to factor, so you don't want to go there. Apr 15 comment SHA1 collision for first 32 bits for two different message I don't believe that the above hashing function actually returns the first 32 bits of the SHA-1 hash; it looks like it returns more; that'd explain a failure to find a partial collision. This question might be better suited for stackexchange, as it's a question about programming, and not cryptography. Apr 15 answered Known Plaintext Attack against 3-round SPECK48/96 Apr 14 answered Is ssl_sign safe as it is using OPENSSL_PKCS1_PADDING Apr 14 revised Majority encryption algorithm? edited tags Apr 14 answered Does OpenSSL apply ASN1 encoding to the hash before signing using ECDSA? Apr 14 comment Comparison of RSA and DRSA scheme using SageMath @PinkimaniGoswami: that DRSA can do most of the encryption computations is useful in some scenarios; however other scenarios can't take advantage of it (as we might need to encrypt a continuous series of messages and so don't have any idle time). However, for both RSA and DRSA, encryption is the fast operation, and so making it even faster may be less of an advantage than if we could somehow precompute the slower decryption operation. Apr 13 comment Inverting RSA using an oracle @TomCorless: nope, you got it; 1% probability (that is, the probability that the Oracle has) is the best you can do. Apr 13 comment How realistic is a dictionary attack on a secure remote password protocol (SRP) verifier? @EliasZamaria: perhaps in initial key establishment; that's actually out-of-scope as far as the protocol is concerned (which cares only about verifying the shared secret, not making them shared in the first place) Apr 13 comment Inverting RSA using an oracle @TomCorless: Look at your step 2: $y_2 = y \cdot y_1^{-1}$; what does that make $x_2$ (assuming success)? Apr 13 answered Inverting RSA using an oracle Apr 13 comment Is there an AES identity key? @abligh: that's not a proof that there's no key that makes AES an identity; one can prove that after 2 rounds, AES isn't an identity, but AES has 10-14 rounds; what happens when you get to the third round is hard to model. Now, it's quite unlikely that there's an AES key, but that's basically what Thomas said... Apr 13 comment How does order-preserving encryption work on string? However, Paillier isn't order preserving. Actually, it's easy to see that no public key encryption system can be order preserving (if it was, then it wouldn't be secure) Apr 13 comment Are there any hash functions that use integers of arbitrary bit size (e.g., int63)? @divisionbyzero: one would expect that a 32 bit rotate would not be expensive on such a system; you would do ((x << n) & mask1) | ((x >> n) & mask2); that's two shifts (or rotates), and three logical operations. Is time so critical that an implementation of SHA-256 that uses those operations would be infeasible? Apr 13 answered Comparison of RSA and DRSA scheme using SageMath Apr 13 comment Calculating characters from the sum of ASCII pairs "this has proven to be rather tedious with short messages alone" - surely, you have a computer doing the searching, don't you? Apr 13 answered security of a block cipher mode of operation Apr 12 comment Non-repudiation in classical cryptosystem Have both sides use hash based signatures to sign their messages?