Linked Questions

36
votes
3answers
7k views

Does "Shattered" actually show SHA-1-signed certificates are "unsafe"?

Note: I am not advocating anyone continues using SHA1-signed certificates: they are dead as far as security is concerned and should no longer be used. I'm just trying to clarify my understanding of ...
17
votes
3answers
12k views

After Google's collision attack, is RSA-SHA1 signature still safe?

Google succeeded to get a collision in SHA-1 last year in an attack called shattered. Does this fact make certificates based RSA-SHA1 Signature risky for creating fraud certificates? If RSA-SHA1 ...
16
votes
1answer
11k views

In 2020, SHA-1 practically broken in chosen-prefix collision (CP-collision). Can double SHA-1 hashing prevent CP-collision?

In a recent study SHA-1 is a Shambles - First Chosen-Prefix Collision on SHA-1 and Application to the PGP Web of Trust by Gaëtan Leurent and Thomas Peyrin. 2020, they showed the first practical chosen-...
12
votes
3answers
11k 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?
7
votes
3answers
10k views

Is it possible to find the key for AES ECB if I have a list of plaintext and corresponding ciphertext?

Assume I have a list of plaintext text and its corresponding ciphertext which was created using a specific key with AES in ECB mode. Can I recover that key? If, how big does the list of plaintext ...
7
votes
2answers
3k views

Argon2 for both password storage and key derivation

Is using Argon2 for both password storage and key derivation secure? I'm planning on using different salt values, of course. The basic concept is something like this: Alice has some secret data ($...
7
votes
4answers
382 views

Can I replace SHA-1 with SHA-512/160 to address Shambles?

The destination is software (within a remote trust boundary) that expects SHA-1 results. Would it be safer for the source (that's within my own trust boundary) to replace my SHA-1 computation at my ...
6
votes
2answers
657 views

SHA-512 - How difficult is it to find a hash digest beginning with at least twelve zeros?

I know it's possible to find a hash value with multiple zeroes in it, I know of some BitCoin hashes with it, but how difficult is it to find/create a hash digest with 12 or more leading hex zeroes in ...
4
votes
5answers
3k views

Why is a too fast hash function not secure?

I understand why we need hash functions to be fast enough for processing but slow enough for security. But I do not get why a very fast hash function can cause a collision. My guess is that a very ...
4
votes
1answer
1k views

Is Mega.nz encryption vulnerable to brute force cracking by quantum computers?

I am interested in Mega.nz cloud storage. It is using end-to-end encryption. It says that it uses AES-128 to encrypt files And there are more details in their white paper But I saw that quantum ...
4
votes
2answers
2k views

Is it hypocritical to use AES-256 and RSA 2048 in the same application?

I see a common claim that AES-256 is the gold standard and is good future proofing, often in the same wind as "just use 2048-bit keys for RSA". Security documents seem to recommend both AES-256 and ...
4
votes
1answer
736 views

Worth taking performance hit of HMAC to gain additional security?

It seems like SHA-512 truncated to 256 bits is usable as a MAC [1]. The advantage is that it's ~50% faster than HMAC-SHA-256 on 64-bit CPUs and ~50% faster than HMAC-SHA-512 on short inputs. (My use ...
3
votes
1answer
132 views

Do ciphers with a key size of 64 bits still have use under very limited attack models?

If we have a very performance critical interactive session, like a video game, running on a trusted platform (video game console). If our goal is to prevent exfiltration of up to date information (...
2
votes
3answers
619 views

3DES security when K1=K3

I am mainly looking for security on 2-key $\operatorname{3DES}$ implementation where $K_1=K_3$. How hard or easy is it to crack $\operatorname{3DES}$ when $K_1=K_3$?
2
votes
1answer
1k views

How long would it take to brute force a 32 or 16 bit integer and which type of processor would brute force this in the shortest period of time

I was actually wondering... How long would it take to crack/brute force a 32 bit key/encryption and a 16 bit key/encryptions respectively on a 4GHZ and a 2GHZ PC. I know that a 32 bit integer has 4,...

15 30 50 per page