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Security and Crypto Technologist


Feb
12
comment Pseudo random permutation for arbitrary size domains
@PaŭloEbermann using FPE with AES-NI is comparable speeds with AES-NI. Feistel networks with 10 or so rounds with AES-NI hardly slows it down .
Feb
12
answered Pseudo random permutation for arbitrary size domains
Feb
12
comment Should tweak be unique per message?
well that is not the point , the TBC can be used in any mode, it is just a block cipher with additional input tweak , for all practical purposes its block cipher and can be used in any mode .
Feb
11
answered Should tweak be unique per message?
Feb
11
comment Should tweak be unique per message?
Tweaks are designed to provide randomness to block ciphers directly rather than using the block cipher in some mode. I cannot agree for few things in the answer. 1. "Tweaks are never used directly", check out the different modes of FPE, tweaks are given directly by the user. 2."None of these needs to be visible to a programmer...", same check FPE. Now with this its appropriate to ask the comparison if its more secure to use a block cipher + IV per message or use a block cipher + same tweak for all messages !
Feb
11
comment Should tweak be unique per message?
if the developer does not need to know about tweak , how is the tweak generated/provisioned/provided as input to encryption algorithm , how is the same tweak provided again to decryption algorithm run in a different machine ?
Feb
11
revised Should tweak be unique per message?
more clarity
Feb
11
asked Should tweak be unique per message?
Feb
4
accepted Is 80 bits of key size considered safe against brute force attacks?
Feb
3
revised Is 80 bits of key size considered safe against brute force attacks?
edited question title
Feb
3
asked Is 80 bits of key size considered safe against brute force attacks?
Feb
1
comment Is knowing the distribution of input domain only way to do cipher text only attacks?
either way would be of help .
Jan
31
revised Is knowing the distribution of input domain only way to do cipher text only attacks?
more clarity
Jan
31
comment Is it ok to send part of digital signature if we have bandwidth constraints?
how would you verify ? if you have only part of signature ?
Jan
31
accepted Impact of distinguishing between random text and cipher text?
Jan
31
accepted implication of tweak on bruteforcing a block cipher
Jan
31
asked Is knowing the distribution of input domain only way to do cipher text only attacks?
Jan
30
comment Block cipher with key longer than block size
but the relation is not established correctly. the factor does not depend on cardinality of block size but cardinality on the set of permutations possible which is the crucial part to be specific
Jan
30
revised Block cipher with key longer than block size
corrected the math
Jan
25
comment Impact of distinguishing between random text and cipher text?
stand corrected