1,037 reputation
38
bio website
location
age 44
visits member for 3 years, 3 months
seen 7 hours ago
programs in C and Perl, mostly

7h
comment PGP Encryption for Files on a Mac
apple.stackexchange.com/questions/121095/…
Nov
23
comment How does hash function in Elgamal signature scheme prevent existential forgery attack?
cs.columbia.edu/~zeph/4261/lectures/…, slide 13
Nov
8
comment Why is g is less than p in Diffie-Hellman?
If $g > p$, then it is the same as if we had chosen $g \mod p$, which is $< p$. We are doing all operations modulo $p$. E.g. modulo $p=7$, it's the same whether we choose $g=2$ or $g=9$ or $g=16$ etc.
Nov
8
answered Why do we need to compute message digest of a message first while signing it?
Nov
8
answered Why is g is less than p in Diffie-Hellman?
Oct
20
comment problem with “one time pad”
This is the Boneh Coursera homework exercise, I think...
Sep
24
awarded  Autobiographer
Sep
8
comment Why verify padding at all?
It still leaves the issue of leaking the final byte from the length...
Sep
8
answered Why verify padding at all?
Aug
17
awarded  Yearling
Jul
4
comment Cryptool - DES (ECB and CBC ) - double encyption
What IV did you use in CBC mode?
Apr
25
awarded  Nice Answer
Apr
23
comment Are the MD5 constants an S-Box?
More original than AES was the use of S-boxes in DES. But the term predates even that, I think.
Apr
19
awarded  Revival
Mar
16
answered Cipher Feedback Mode
Mar
16
answered Question on RSA trapdoor permutation
Mar
8
answered Number of possible keys in a Play fair cipher
Mar
5
answered How to decrypt 3DES in ECB mode (using a wordlist)?
Mar
2
comment File Encryption (EFS method)
And, as an afterthought, DPAPI has a mechanism to avoid re-encryption of secrets (like RSA private keys) protected by it, when a user changes its password. This is an added benefit.
Mar
1
comment File Encryption (EFS method)
DPAPI has several purposes in Windows besides encrypting the RSA private key (to encrypt other secrets like WiFi passwords, and IE account passwords etc.); moreover the hash from the password is used only after thousands of iterations (and a random salt) provided by the DPAPI API. This slows down direct cracking attacks on the encrypted secret key, if the NTHash is not available, e.g.