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| bio | website | github.com/CodesInChaos |
|---|---|---|
| location | Munich, Germany | |
| age | ||
| visits | member for | 1 year, 11 months |
| seen | 1 hour ago | |
| stats | profile views | 112 |
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Jul 6 |
comment |
“SHA-256” vs “any 256 bits of SHA-512”, which is more secure? I'd even say it's more secure, since state collisions become much harder, protecting against a certain class of multi-collisions. It also prevents length-extension. |
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Jul 5 |
revised |
Is the Blum Blum Shub PRNG suitable to create initialization vectors? added 98 characters in body |
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Jul 5 |
comment |
128-bit Pseudorandom number Generator @fgrieu I think it's a bit misleading to say he needs a true RNG. He needs a well seeded secure PRNG. |
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Jul 5 |
answered | Is the Blum Blum Shub PRNG suitable to create initialization vectors? |
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Jul 4 |
comment |
Stream ciphers based on discrete logs It's important to note that most of these reductions only apply in the asymptotic limit, and make no useful statement about the security of realistic key sizes. |
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Jul 1 |
comment |
Proof of work for standard computers I already considered this idea. The main issue with this idea is that you store the output in shared memory, allowing an attacker to use a high number of workers on that memory. So it still fails 3. |
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Jun 30 |
asked | Proof of work for standard computers |
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Jun 30 |
comment |
How are state wiretaps obtaining plaintext from encrypted transmissions? First two seem most likely to me. |
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Jun 27 |
comment |
Asymmetric algorithm to generate compact unique messages that can be validated I disagree with turning this into a comment. Why would do you think this is no answer? |
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Jun 27 |
answered | Asymmetric algorithm to generate compact unique messages that can be validated |
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Jun 27 |
comment |
Asymmetric algorithm to generate compact unique messages that can be validated There are smaller elliptic curves. You'll get reasonable strength for 160 bit curves, with 40 byte signatures. But a signature by itself is useless, you need a message you want to sign. To make that message unique, you might want to use a 16 byte nonce. |
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Jun 27 |
comment |
Asymmetric algorithm to generate compact unique messages that can be validated If both sides have a keypair, and they know each other's public key, you could run a key-exchange algorithm to get a shared symmetric secret between these two parties. Then use that to calculate a MAC of a nonce. Assuming a 16 byte nonce and a 16 byte MAC, you get 32 bytes total. But in its plain form this will be open to replay or MitM attacks. |
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Jun 27 |
comment |
Asymmetric algorithm to generate compact unique messages that can be validated Two questions: 1) Should the consumer be able to prove to third parties that the message came from the producer? 2) What about replay attacks and MiTM? | You should start in the very beginning, and describe the goals of your protocol. |
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Jun 27 |
comment |
Asymmetric algorithm to generate compact unique messages that can be validated Your steps 2 and 4 are badly written. "encrypt with private key" is the case for RSA, but not most other signature algorithms. You also neglected to mention padding, which is essential for RSA signatures. |
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Jun 26 |
comment |
How much bigger does a precomputed lookup table get when salt is added? You don't even need salts that large. You don't need to make creating the table infeasible, it's enough to make multi-target attacks less efficient than single target attacks. For user password-hashes, 64 bits is plenty. |
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Jun 26 |
comment |
How much bigger does a precomputed lookup table get when salt is added? I don't get why you're talking about the number of users. |
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Jun 23 |
comment |
bcrypt - collision-resistance against chosen salt and work factor? I'm not sure why you require collision resistance here. Shouldn't first pre-image resistance be enough? |
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Jun 23 |
revised |
Does it make sense to use slow hashes in digital signatures? added 824 characters in body |
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Jun 23 |
answered | Does it make sense to use slow hashes in digital signatures? |
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Jun 23 |
comment |
What is the difference between these AES encryption methods I've added a comment pointing out what's wrong with that article codeproject.com/Articles/15280/… |
