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9h
comment Double the key in block cipher - which approach is better?
Xoring $k_2$ into both then plaintext and the ciphertext is better that xoring it only into one Even Mansour construction
12h
comment Security of this deterministic encryption scheme
Implementing this scheme without a padding oracle isn't trivial, unless the MACed plaintext is already padded.
13h
comment Winrar password extracting
I can't say for sure without having looked at the winrar crypto in detail, but I consider it pretty unlikely since it'd require an unusually dumb mistake. Probably the best you can do is running a program that tests many password candidates, but that's only feasible for simple passwords.
13h
comment Winrar password extracting
Known plaintext attacks don't work against modern ciphers.
13h
comment Block Ciphers - Standardize plain text
@AlexRibeiro CTR produces the key stream by encrypting a sequence of counters. While you compute a key stream consisting of full blocks, you can simply discard the useless final bytes. CTR can do that, since it doesn't pass the ciphertext blocks to the blockcipher when decrypting, instead passing the same counters as when encrypting.
13h
comment Unblind a RSA blinded signature
Your post might be easier to read if you replace those parentheses by =. Or perhaps do the sample calculation in a separate paragraph.
17h
comment Bouncy Castle and Salsa 20
I'm voting to close this question as off-topic because it is a programming problem, not a cryptography problem.
19h
comment How does bitmessage encryption work?
Since somebody creating two public keys with the same address doesn't look like a relevant attack, this only relies on (multi-target) second pre-image resistance, not collision resistance. 160 bits is plenty for that.
1d
comment Machine readable, user non-readable - XML file
I'm voting to close this question as off-topic because it is about obfuscation, not cryptography.
2d
comment Getting the encryption/has algorithm used for modem configuration file
The full hash is still visible in the edit history. If you want to get rid of it, you need to contact the stackexchange team.
2d
comment Is algorithm with more than $2^{word size}$ words secure?
Do you assume that the wordsize is half the blocksize?
Jun
26
comment HMAC definition by using only one key
@SEJPM I don't have any plans for writing an answer to this question.
Jun
25
comment what is possibility of collision in djb2 function?
I'm voting to close this question as off-topic because this isn't a cryptographic hash.
Jun
25
comment Program to generate a secure 128 bit key on a windows machine
@VincentAdvocaat You could ask on [softwarerec.se] or you could use my comment.
Jun
25
comment Program to generate a secure 128 bit key on a windows machine
I'm voting to close this question as off-topic because it's a software recommendation question and not about cryptography itself.
Jun
25
comment Program to generate a secure 128 bit key on a windows machine
Download LINQPad, choose "C# statements" and paste this code: var bytes=new byte[16]; new RNGCryptoServiceProvider().GetBytes(bytes); BitConverter.ToString(bytes).Replace("-","").Dump();
Jun
25
comment Program to generate a secure 128 bit key on a windows machine
Why use PSK suites? They're lacking basic security features like forward secrecy.
Jun
25
comment Why is HMAC-SHA1 still considered secure?
@user93353 Depends on what you want to achieve. Of course no unkeyed hash is a MAC.
Jun
25
comment Why is HMAC-SHA1 still considered secure?
@user93353 Like I said, the security of HMAC-SHA1 depends on the unknown key. If there is no key or it is known to the attacker, the collisions in SHA1 become a threat. But SHA1 should rarely be used in designs, since there are better alternatives available.
Jun
25
comment Why is HMAC-SHA1 still considered secure?
Should we close this as a duplicate of Is HMAC-MD5 considered secure for authenticating encrypted data?? While this question is about SHA1, not MD5, the answer is nearly the same.