Linked Questions

1 vote
1 answer
210 views

Are sufficiently large key sizes enough to deter quantum attacks for symmetric key ciphers? [duplicate]

Are sufficiently large key sizes enough to deter quantum attacks for symmetric key ciphers such as AES?
Nathan Aw's user avatar
  • 2,277
26 votes
7 answers
6k views

Does Terra Quantum AG break AES and Hash Algorithms?

According to this Bloomberg article: A Swiss Company Says It Found Weakness That Imperils Encryption Terra Quantum AG has a team of about 80 quantum physicists, cryptographers and mathematicians, who ...
kelalaka's user avatar
  • 48.9k
16 votes
3 answers
24k views

Has AES-128 been fully broken?

Has AES-128 been broken over the full 10 rounds? If so, by what means? By a commercial entity? By a supercomputer? If not, why is AES-256 used to replace AES-128 so frequently?
Offir's user avatar
  • 283
14 votes
5 answers
10k views

Does Grover's algorithm really threaten symmetric security proofs?

By Shannon's theorem of perfect security, if I give you a ciphertext 'LOUPL', you can do a brute-force attack and then you would find plaintexts like 'HELLO', 'APPLE', 'SPOON', but you can't ...
Victor Espinoza's user avatar
4 votes
11 answers
9k views

For Symmetric Cryptography, why is it considered more important to safeguard a key than the function/algorithm for encrypting/decrypting a message?

As stated for the question above here's an analogy: You are a robber looking for a house to rob with two different scenarios that might occur. 1. You have a key that you know belongs to a house and ...
omar7439's user avatar
15 votes
2 answers
8k views

What is the correct way to implement PBKDF2 + AES CBC + HMAC?

I've been doing a lot of reading on the proper way to implement AES CBC mode with HMAC authentication. I've seen many explanations, however, I've had a hard time finding an actual real example (with ...
izzle's user avatar
  • 591
8 votes
2 answers
2k views

Could quantum computers "break" symmetric crypto-systems (e.g. AES)?

These days I'm reading about quantum computing and quantum cryptography which I've found extremely interesting. Well, I also read some blog posts of Bruce Schneier talking about how quantum computers ...
user avatar
2 votes
3 answers
12k views

OpenSSL AES 256-bit Key Management

I am using C and OpenSSL to encrypt files. After experimenting with the OpenSSL command line utility, it makes you enter a passphrase that can be any length, but uses that to create a 256-bit key. ...
mrobillard's user avatar
1 vote
2 answers
3k views

How weak is using AES with a 128 bit key but 64 bits of the secret key are public constants?

Respected community, I was wondering how weak would AES-128 be, if we provide only a 64 bit key with the other remaining 64 bits either zero bits or public constants, known to the attacker. Is it easy ...
Aravind A's user avatar
  • 1,030
2 votes
1 answer
5k views

What are the known weaknesses in AES and is it being considered for upgrade or replacement? [closed]

I was at a conference earlier this week sponsored by a library about data archiving. The conference was not about cryptography. One of the speakers said that the Advanced Encryption Standard (AES) was ...
vy32's user avatar
  • 439
-2 votes
1 answer
524 views

Is AES practically unbreakable? [duplicate]

Is AES practically unbreakable? Is brute force attack practical on AES?
Fathima Abdur Rahman's user avatar
1 vote
1 answer
236 views

Why can´t an attacker find the key if he has the plain text, the IV and the ciphertext? [duplicate]

I am reading a book about web security and they are now talking about AES CBC. After reading the chapter I was wondering, can an attacker compute my secret key if he has access to the IV, the plain ...
Daniel Oliveira's user avatar
1 vote
1 answer
145 views

Why did NIST Post Quantum Standardization have 2 schemes?

NISTs Post Quantum Standardization process selected Kyber as the KEM scheme. I'm a bit confused over why NIST would standardize for a 'scheme' and not just a 'cipher'. Does Crystals-Dilithium use a ...
keithRozario's user avatar
1 vote
0 answers
293 views

Which block cipher modes of AES-256 are quantum safe? Is OCB mode quantum safe?

I was wondering if I have to keep my data safe in an age when quantum computers become a reality. Which AES block cipher modes will be secure? Will AES-OCB will be quantum safe if used in a PGP like ...
ANISH M 18CS006's user avatar
0 votes
0 answers
92 views

Cryptographic strength of AES-GCM-256 for classical and Quantum

How can the strength be calculated, of both the GMAC and the encryption for AES-GCM-256, with AES key of 256 bit, for classical and quantum computers?
Evgeni Vaknin's user avatar

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