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May
11
comment ECC vs RSA: how to compare key sizes?
You could ask on / take hints from the TEX site.
May
11
reviewed Leave Open Diffie Hellman Exponentiation Implementation Problem
May
11
reviewed Close At what point can you you implement crypto algorithms?
May
10
answered with RSA encryption, how do I find the md5sum of the private key from the public key?
May
10
comment with RSA encryption, how do I find the md5sum of the private key from the public key?
Besides the quite obvious issue with regards to recovering the private exponent (or CRT parameters) first, you can only create a hash over a binary representation of a key. Sometimes a hash over the modulus of a key pair is used as identifier, you might mean that...
May
10
reviewed Approve with RSA encryption, how do I find the md5sum of the private key from the public key?
May
10
comment Pailler encryption of small integers to 32-bit integers
@VadymFedyukovych BigInteger and SecureRandom are already part of the Java SE. Bouncy simply reuses those.
May
5
comment Decrypting DES - limited information
If the IV is incorrect in CBC mode then only the first 16 bytes of plaintext will be corrupted. So look at the end of the decrypted plaintext.
May
4
comment Clefia Vs AES 128 bit
Meh, I created 2 versions of hex decoder with a difference of 100K. Removing API calls and a few branches (all of them actually, except the for loop and one final check). 10K dif is completely possible.
May
4
comment Clefia Vs AES 128 bit
Depends on context. In this case it could mean software optimized for speed. Think loop unrolling, larger state, lookup tables, minimize variable use etc. Compare the Android versions :) The answer of orlp is clearly targeting hardware speed optimization (or acceleration) cause it says so :)
May
4
comment trying to get calculator and RSA calculatin does not make sense
I use RealCalc and of course the WolframAlpha app.
May
4
comment Clefia Vs AES 128 bit
That's interesting information Tony. This does point out a clear advantage about AES though; it's more widely implemented so you would expect more speed optimized implementations of it. Note that Bouncy Castle has 3 versions of AES in case you want to test further.
May
4
comment The difference between MAC algorithms and what to use
@jww That part particularly mentions MAC using ciphers (actually it seems to recommend CBC-MAC but this is an old text). As you can see I already made a distinction in the text between HMAC and other MAC's. Unless a mathematical connection between the cipher and hash is discovered you would have to reverse the hash in case of a HMAC. In effect you should not be using the same cipher construction for the encryption and MAC and separate keys should indeed be preferred.
May
4
comment Format preserving encryption FFX
Just in case somebody gets confused: if a cipher doesn't have integrity and authentication then it doesn't automatically mean that the cipher is malleable.
May
4
comment Format preserving encryption FFX
Question: if most plaintext aren't valid, couldn't you save up bits and add an authentication tag? If there are enough bits available you could even forgo FPE completely. Is there any calculation that can be performed in this regard? Happy to post this as a separate question is this is too complex here...
May
3
comment Format preserving encryption FFX
I presume TPRP stands for Tweakable Pseudo Random Permutation here?
May
3
comment Energy necessary for brute-forcing or decryption
The pass phrase in this case is about 129 bits of entropy. Together with stretching is is probably harder to attack than factoring the modulus. Symmetric algorithms may be harder to attack with a quantum computer than asymmetric algorithms for about the same amount of security. Or not?
May
3
comment Clefia Vs AES 128 bit
From their site: "You can use CLEFIA Information only for the purpose of your evaluation of CLEFIA. You may not develop or manufacture any products by using CLEFIA Information without the prior written approval of Sony. In addition, you agree not to quote, reprint, modify, port, translate, transform, create derivative works of or any other adapt CLEFIA Information, in whole or in part." Now this could be a leftover from the time before standardization, but it could also mean that Sony are a bunch of bastards. I'm not betting anyway.
May
3
comment Clefia Vs AES 128 bit
Please note that the IP rights of CLEFIA are not well stated by Sony - even though they have been offered for standardization. Download any code from Sony at your own risk.
May
3
comment The difference between MAC algorithms and what to use
@eBusiness Right you are of course, moved that entry up. Also changed hash to MAC, must have been late at night :) Thanks for the heads up.