19,438 reputation
12676
bio website
location Paris, France
age
visits member for 2 years, 11 months
seen 3 hours ago

I'm an engineer with experience in applied cryptography, in particular in Smart Card systems.


17h
comment Rainbow table for DES with all-zero plaintext?
I read there are two canonical improvements to that: $\;$ 1) Rivest's distinguished points, iterating encrypt-then-truncate starting from a point in some subset of the keyspace (e.g. with some 16 bits at zero) until reaching such subset, for a modest but welcome reduction in memory requirement; and $\;$ 2) rainbow tables, which seem to originate in: Philippe Oechslin's Making a Faster Cryptanalytic Time-Memory Trade-Off, in proceedings of Crypto 2003.
18h
comment Rainbow table for DES with all-zero plaintext?
M. E. Hellman, A Cryptanalytic Time-Memory Tradeoff, IEEE Trans. on Info. Theory, Vol. 26, July 1980, pp. 401-406. $\;$ At least that one is relatively straightforward! It does not use what otus's answer and comment describes as the rainbow improvement, and I wonder how much that improves the time-memory tradeoff.
1d
comment Rainbow table for DES with all-zero plaintext?
In addition of things I do not grasp with rainbow tables (see updated question): why the $\oplus i$ term?
1d
revised Rainbow table for DES with all-zero plaintext?
Addition stating my ignorance
1d
comment Understanding Lattice based cryptosystem
@pushpen.paul: It seems that the Wikipedia entry, or/and for this or that example it cites, is enough to answer what makes lattice based system strong? with: for many, the hardness of the Closest Vector Problem in some appropriate lattice. Perhaps, state this and ask for more, e.g. what the CVP is, or why it is believed to be secure even with quantum computers?
1d
comment Compression function to guarantee randomness of one time pads?
A bziped file starts 42h 5Ah; not good for a keystream! There are a lot of other redundancy, including markers of compression settings, and at least one error detection code. More generally, for many existing compression algorithms, the output is distinguishable from random even if the input is not; often, the distinguisher can simply be: decompresses without error.
Jul
26
revised Rainbow tables and blowfish
Add rainbow-table tag
Jul
25
revised Idea for user/pass hashing to prevent rainbow tables, would it work?
Add rainbow-table tag
Jul
25
revised How does using salt reduce rainbow table attack?
Add rainbow-table tag
Jul
25
revised How can rainbow tables be used for a dictionary attack?
Add rainbow-table tag
Jul
25
revised Why must we hash lot of times in rainbow tables?
Add rainbow-table tag
Jul
25
revised Is rainbow table attack applicable to any hash?
Add rainbow-table tag
Jul
25
revised Example Rainbow Table Generation
Add rainbow-table tag
Jul
24
reviewed Reviewed Vigenère cipher: Security when key length and plaintext length are the same
Jul
24
comment Calculating periodicity of a pseudo random number generator (Middle-square method)
This question is squarely off-topic on crypto.SE because it is about a non-cryptographic Random Number Generator.
Jul
24
revised What security authorities and standards reject $e=3$ in RSA, when, and with what rationale?
typo
Jul
24
reviewed Close LFSR and Markov chain question
Jul
24
revised What security authorities and standards reject $e=3$ in RSA, when, and with what rationale?
typo
Jul
24
revised What security authorities and standards reject $e=3$ in RSA, when, and with what rationale?
Clearly state my opinion
Jul
24
revised What security authorities and standards reject $e=3$ in RSA, when, and with what rationale?
Include links to RGS and its approval, with corrected date; state main change