196 reputation
6
bio website
location
age
visits member for 8 months
seen 3 hours ago

Apr
9
comment Is it possible to deduce the IV from CBC ciphered data, without knowing the key?
I cannot get why it must to be unpredictable. Are there any weakness known?
Mar
29
comment How is the curve equation used in ECC?
A (relatively easy to understand) primer on elliptic curve cryptography arstechnica.com/security/2013/10/…
Mar
14
comment AES encryption takes more time to decrypt than encrypt
If you're interested in a efficient implementation and understand how one can table a lot to compute an AES encryption roud I suggest to read this paper: link.springer.com/chapter/10.1007%2F3-540-36400-5_13#page-1 (slides are available here: chesworkshop.org/ches2002/presentations/Bertoni.pdf)
Feb
24
comment Decode message $m = p * q$, where $p ^ 5 \bmod N$, $q ^ 5 \bmod N$ and $N$ are known
And knowing $m^2$ and $p^5$? because you could use the fact that $GCD(2, 5)= 1$ and $GCD(m^2, p^5) = p^2$ ?? Just an idea, not tried
Feb
5
comment Can anyone explain most popular RSA attacks like I'm 5?
Dolev, Danny; Dwork, Cynthia; Naor, Moni (2000). "Nonmalleable Cryptography". SIAM Journal on Computing 30 (2): 391–437. doi:10.1137/S0097539795291562.
Feb
4
comment Can anyone explain most popular RSA attacks like I'm 5?
I mean that you can modify the ciphertext to get a modification (under you control) on the plaintext. I'll try to add a reference here when I get access to my computer. At the moment you could check this Wikipedia page: en.m.wikipedia.org/wiki/Malleability_(cryptography)
Jan
21
comment AES mode for file encryption
You should read this page en.wikipedia.org/wiki/XEX-TCB-CTS to get some hints on modes that are intended for file system encyption. You'll have better performances and security. other good resource: truecrypt.org/docs/modes-of-operation
Dec
3
answered Graphically representing points on Elliptic Curve over finite field
Dec
3
comment $\phi$ function in Dual_EC_DRBG
Another resource on the backdoor and how to exploit it: jiggerwit.wordpress.com/2013/09/25/the-nsa-back-door-to-nist (I think this was the most clear article I read on the subject)
Oct
2
comment how to iteratively calculate a^emod n with modulus n sized 4096 bits
Interested in that article
Sep
28
awarded  Commentator
Sep
18
comment Can we design a public-key infrastructure without certificate authorities?
There is the Identity Based Encryption, where the public key is, say, your email address or your name.surname or your social security number or ... You still need a trusted authority to ship the corresponding private key.
Sep
13
awarded  Critic
Sep
4
comment Can anyone explain most popular RSA attacks like I'm 5?
Textbook RSA is not probabilistic and it is malleable.
Sep
3
comment Using one-way hash functions as the encryption method
Yes, I agree. But it is still not secure. It is not IND as a start (try to encrypt a message $m_1 = A A A A A$ and a $m_2 = A B C D E$ [every single letter is a single word]).
Sep
3
answered Why the symmetric key layer in PGP?
Sep
3
answered Using one-way hash functions as the encryption method
Sep
3
comment Why the symmetric key layer in PGP?
I think you misunderstood a detail of PGP encryption. Only the random symmetric key is encrypted under the recipient's (asymmetric) public key. This way to encrypt stuff is quite common and is called KEM/DEM paradigm: Key Encapsulation Method/Data Encapsulation Method oy Hybrid Encryption. Some refs: en.wikipedia.org/wiki/Hybrid_cryptosystem and en.kryptotel.net/encryption.html
Sep
2
answered Initialization vector in symmetric-key encryption
Aug
23
answered Is it possible that two distinct RSA moduli share both of their prime factors?