Tag Info

New answers tagged

2

Symmetric algorithms are secure post-quantum, only with less bits of security (usually about half). That means you only need to care about the authentication and key exchange parts of the cipher suite. Suites that don't use public key authentication or key exchange, i.e. preshared key suites, are post-quantum secure, but not useful in most usecases. There ...


0

The question whether SSL/TLS is used for maintaining data confidentiality, is actually not as straight-forward as one might think. It depends. We might disregard the deprecated SSL cipher suites that provided authenticity and integrity with a NULL bulk encryption algorithm. Even if you only take the cipher suites that do encrypt the bulk contents into ...


2

The answer to the first question is both. TLS uses a custom PRF based on HMAC to generate symmetric and MAC keys from a shared secret. The shared secret is created during the asymmetric key exchange between client and server as part of the handshake. The PRF generates key material of a required length. That length is determined by the key sizes and the key ...


2

Yes, the MAC algorithm works the same way on both sides. It is a mathematical function that computes the tag from the key and the message. On the sender side, the message is processed as follows: Calculate T = MAC(key, raw_message). Send the raw_message and the tag value T. Many communication protocols append them in this order but anything will do as long ...


1

Two things to consider: encryption and authentication. In general you can only say that a cascade of ciphers is as secure as its weakest link. If the encryption in NaCL had a side-channel attack, it might leak information about the plaintext, whether or not the ciphertext is sent through TLS. Authentication, on the other hand, is additive. If you can ...


2

SHA is related to AES in that they are both US government standards. They are not similar algorithmically. SHA and AES are cryptographic primitives, TLS is a protocol. As the name describes SHA is a family of hash algorithms. AES is a block cipher. TLS uses many encryption algorithms, including AES in various modes, and several hash algorithms, including ...


2

Short answer, before someone marks this as a duplicate or answers it with an essay or something: You're exactly right. This was one of the biggest consequences of the infamous Heartbleed exploit in OpenSSL, which exposed the memory of processes using OpenSSL for TLS to anyone with an Internet connection. It's also significant for cold boot attacks, where ...



Top 50 recent answers are included