39 questions linked to/from How reassuring is 64-bit (in)security?
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### Finding the cleartext password given its MD5

Given powerful GPU and PC hardware, is it realistic to recover a password in a few hours given a cleartext's MD5? Max chars are 95, and the maximum length of the password is 15 characters.
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### 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 ...
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### 80-bit vs 128-bit security in today's world

In today's world of applications, I see a lot of the time a 256-bit encryption key is used, but what about an 80 or 128? What makes 256 the one to use. Is a 80 or 128 easily decrypted? Are comp ...
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### Brute force strategy

I am a beginner in this field, and I was thinking about brute force strategies to break symmetric key encryption. Let's say we have a block cipher in CTR mode and the key is 56 bits in size. What ...
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### How long would it take all of the supercomputers or cloud computing on Earth to bruteforce a significantly long password?

I was arguing with a colleague who thinks that SHA256 (password + 64 character static salt) is "insecure." My argument is that nothing in cryptography is "secure," it's all a ...
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### Is it theoretically possible to create an unbreakable cipher?

I know this question might sound strange, but is it theoretically possible to create an unbreakable cipher if we don't consider bruteforce? Some of us believe that it is possible to create ciphers and ...
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### 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 ...
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### Recovery Passphrase Collission for BIP-39 and BIP-44

Referring to the standards of [BIP-39] and [BIP-44]: a 'master password' consisting of 12 words uniformly selected from a 2048-word dictionary corresponds to 128 bits of entropy, that is then used as ...
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### 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 $K_1=K_3$?
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### 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,...
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### How to calculate time needed for decryption of 64-bit key

I am having trouble figuring out how long it takes to decrypt a 64-bit key, given that a computer can do 1 billion trials per second. I know that there are $2^{64} = 1.844 \times 10^{19}$ possible ...
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### 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 (...
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### Can Trivium ciphertext be decrypted by an adversary if the key is known, but the IV is not?

Suppose that the adversary is able to recover the key of Trivium cipher. But the associated IV is unknown to him. Will he be able to decrypt the ciphertexts without any complexity?