9,417 reputation
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bio website github.com/CodesInChaos
location Frankfurt, Germany
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visits member for 3 years
seen 10 hours ago

Nov
5
reviewed Approve suggested edit on Why is $-1$ an illegal message in the Goldwasser-Micali Encryption Scheme
Nov
5
reviewed Approve suggested edit on Generator for Group $QR_{N}$
Nov
4
comment random access stream cipher
There are random access stream ciphers, such as AES-CTR or Salsa20. But they are problematic since they can easily lead to two-time-pads. I think the closest you're going to get is XTS which needs to encrypt a few bytes close to the data you want to read.
Nov
4
comment McEliece Public Key Encryption
Zero is also an acceptable error probability.
Nov
2
comment RSA 896 vs 1024 vs 2048 in Javascript?
Since SSL already blocks most attacks, the gain by using JS crypto on top of that can only be meaningful with keys that even a powerful attacker can't break. At minimum 2048 bit RSA or 224 bit ECC.
Nov
1
reviewed Reject suggested edit on Why does WPA-PSK not use Diffie-Hellman key exchange?
Nov
1
comment How to Distribute the Shares using Secret Sharing for arbitrary Monotone Access Structures
@DrLecter I'm not sure if your edit made the question requirements stricter. The OP might be happy with different weights for each secret holder without being handle the general case.
Nov
1
comment Does ssl_rsa_with_rc4_128_md5 have known weaknesses?
For online banking you only face ordinary criminals and long term security isn't essential either. So this should be fine. But I wouldn't be comfortable with it when security requirements are high. Long term RSA key used for confidentiality => no forward secrecy, possibly too small RSA key and RC4 has known biases.
Nov
1
reviewed Approve suggested edit on What is the recommended replacement for MD5?
Oct
31
revised How to calculate entropy of a combined key
added 39 characters in body
Oct
31
reviewed Approve suggested edit on monotone-access-structure tag wiki excerpt
Oct
31
answered How to calculate entropy of a combined key
Oct
31
reviewed Approve suggested edit on How to calculate entropy of a combined key
Oct
31
reviewed Approve suggested edit on How are IVs used in association with RSA Encryption?
Oct
31
comment How are IVs used in association with RSA Encryption?
What's funny about using random padding is that we usually encrypt random symmetric keys (as part of hybrid encryption), a scenario where randomness isn't actually required.
Oct
31
reviewed Approve suggested edit on If I have the unencrypted text and the encrypted text, can I calculate the key?
Oct
31
comment If I have the unencrypted text and the encrypted text, can I calculate the key?
This is a "known plaintext attack" and if you use a modern algorithm properly you'll be immune to it.
Oct
31
comment How to develop a public key cryptosystem based on a hard problem?
@DrLecter I didn't say that you need that specific property. But that you need a non trivial mathematical property beyond one-way-ness. Commutativity is one example, many other schemes rely on a trapdoor. The chance that an arbitrary hard to invert function has such a property is very small.
Oct
30
reviewed Approve suggested edit on Are there any differences in operation between existing Diffie-Hellman specifications?
Oct
30
comment How to develop a public key cryptosystem based on a hard problem?
We know many many hard to invert functions, but only a handful of fundamentally different asymmetric encryption/key-exchange schemes.