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Feb
2
answered How does RIPEMD160 pad the message?
Feb
2
revised Help with AES decryption with AES-NI Instructions
Add rationale
Feb
1
revised Help with AES decryption with AES-NI Instructions
Fix
Feb
1
answered Help with AES decryption with AES-NI Instructions
Feb
1
comment total effective key length of the AESX-192
@poncho: indeed, my mistake. That makes the question more interesting.
Feb
1
revised total effective key length of the AESX-192
retag
Feb
1
revised Why does image size increase after steganography?
typo
Feb
1
awarded  implementation
Jan
31
revised Why does image size increase after steganography?
Polish
Jan
31
answered Why does image size increase after steganography?
Jan
31
comment How to calculate plaintext from modpower cipher
If $a$ is among a small known set (e.g. is the name of a classmate on the call roll per some encoding), and $n$, $e$, $b$ are known, then we much likely can find $a$ by trial and error.
Jan
31
revised steganography of an mp4 file
retag and retitle
Jan
31
comment Proving property of Modified Rabin Signature
Hint: prove that $p=3\pmod4$, $p$ prime, $q=3\pmod4$, $q$ prime, $n=pq$, $\gcd(x,n)=1$ implies $x^{\frac{(p−1)(q−1)}{2}}-1\equiv0\pmod p$ and $x^{\frac{(p−1)(q−1)}{2}}-1\equiv0\pmod q$; then use $p\ne q$ and conclude.
Jan
31
comment Why does image size increase after steganography?
With no info on the steganography technique used, we can only state a generality: compression set aside, in a steganography technique sending an image within an image, the output of the encoder is the hidden image, and the apparent image, so by an entropy argument some natural value of the output size is the sum of the input sizes. That said, it is entirely conceivable to make a steganography encoder that compresses to the point that the output of the encoder is smaller than either of its inputs.
Jan
30
reviewed Approve RSA numerical questions
Jan
29
comment Is H'(M)=5*M + 9*H(M) mod 2^n a secure hash?
@Meysam Ghahramani: the question is interesting, but please fix the erroneous statement about NP-hardness.
Jan
29
revised Are there reasonably secure online voting implementations e.g. for student council elections?
polish
Jan
29
revised Are there reasonably secure online voting implementations e.g. for student council elections?
polish
Jan
29
revised Are there reasonably secure online voting implementations e.g. for student council elections?
Polish
Jan
28
comment RSA-OAEP: How does it work?
@今天春天: yes, except that what you call "standard RSA" is hardly standardized (though close to PKCS#1v1.5 format 0), and usually is called textbook RSA encryption, RSA encryption with no padding, (textbook|raw|bare|naked) RSA public-key|encryption primitive|function. More strictly speaking, RSA Encryption Primitive , noted RSAEP, is step 3b).