Key-stretching adds additional security to potentially weak keys by requiring an expensive computation to transform the initial key into a derived key.

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11
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3answers
402 views

Can I use the same password both for SRP and for client-side encryption?

Suppose a less-than-trusted server is used to store users' confidential data (encrypted at the client side), and both tasks - authentication and encryption/decryption - should be doable with a single ...
3
votes
1answer
2k views

BCrypt+SHA256 vs PBKDF2-SHA256

From this question, the OP posited taking a user's entered password, running it through BCrypt, then running that through SHA256 to produce a 256-bit password-derived key. (EDIT: To clarify, these two ...
2
votes
2answers
273 views

Is upgrading key-stretching algorithms and/or repetitions a thing?

Consider back in the 90s you're ahead of the curve, you hashed and salted your passwords with SHA, and you're a big site, millions of accounts, etc. Well the web evolves, and over time more advanced ...
1
vote
2answers
143 views

Should hashing hashed hashes colide or not?

Since key stretching basically boils down to hashing hashes over and over again (where salt, pepper and password individualize the hash function, but the principle remains the same), I wonder about ...
0
votes
2answers
110 views

Password stretching using concatenation of hashes

I'm working on a simple file encryption tool. Basically, here's how my program works: password = get_user_typed_password() salt = uuid4() key = bcrypt(password + salt) cipher = AES(key) for block ...
0
votes
1answer
66 views

Seeking help with implementing SCRAM in .NET

I'm late to the party and need to be caught up. I'm doing my homework looking things up. I know that I don't want unsalted challenge-response CRAM, I want salted challenge-response SCRAM. I think ...
0
votes
1answer
218 views

Should I run my password through Bcrypt before using it for encrypting a file with AES-256? [duplicate]

I need to encrypt a file with a password that can be memorized. So I was thinking about running the password through some rounds of Bcrypt before using it for AES encryption, so every time I want to ...