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comment AES Encryption using CBC/PKCS5 padding in python while decrypting in java it is given below error
I'm voting to close this question as off-topic because it is about code
May
26
comment Would this be a plausible authenticated encryption scheme using nested encryption?
This answer's formatting is a bit garbled and wall-of-text...
May
25
revised Would this method deliver a perfectly non-malleable encryption for at least two blocks?
edited title
May
25
revised Would this method allow fast authenticated encryption using only a single encryption and RNG operation per block?
edited title
May
25
comment Would this method allow fast authenticated encryption using only a single encryption operation per block?
@Anon2000 I have removed the [flawed] tag from the title of this question (and of your other questions). There is no need to put the status of the question in its title, since it's already at the top of the question body, and the square bracket suffix notation is already used on the stackexchange network to signal duplicates/closed questions, so it's a bit confusing.
May
25
revised Would this method allow fast authenticated encryption using only a single encryption operation per block?
remove [flawed] tag
May
24
comment Product of Sophie Germain Primes and safe primes
Would you like fries with that sir?
May
23
comment Factorization of a number obtained by a modular multiplication operation can reveal factors of the used operands?
"Works" for $n = 3$ as well, if the remainder of $ab$ is 2 mod 3 then one of $a$, $b$ must be 2 mod 3, and the other must be 1 mod 3. Similarly if $ab$ is 1 mod 3 then $a$ and $b$ must have the same remainder mod 3... (ignoring the trivial case where $ab$ is divisible by 3). Not sure how much useful information that leaks though.
May
19
revised Building a combined encryption scheme from two encryption schemes that's secure if at least on of them is secure
rolled back to a previous revision
May
11
comment Is the “Matryoshka Cipher” possible to write and implement?
You would probably have more hits by searching for "cascade cipher" or "cascading cipher", which is basically the same thing.
May
9
comment Diffie Hellman Exponentiation Implementation Problem
possible duplicate of How do institutions like banks do RSA with big primes?
May
4
comment Is ECB mode safe to use with RSA encryption?
RSA is not a block cipher and you shouldn't use it as one.
May
3
comment Why is it a bad idea to use Diffie-Hellman with a prime such that $p - 1$ is smooth?
@user24258 The order of the multiplicative group of integers modulo $p$ is $p - 1$. Loosely stated, if $p - 1$ is a product of only small factors, then you can "break down" the problem of solving DH in a group of order $p - 1$ to the problem of solving DH in a bunch of groups of way smaller order.
May
3
comment How to decrypt unusual Many Time Pad
Hint: rewrite "random[0] xor random[1] = cipher[0]" as "(all-zero plaintext) xor (random[0] xor random[1]) = cipher[0]". is this really a many-time pad? Do cipher[0] and cipher[1] actually carry any information, or are they in fact statistically independent from random[1]? Write down the probabilities on paper to make sure.
May
1
comment Block cipher does not provide security by itself
Where does the statement come from? It's meaningless with context.
Apr
30
comment Why are there no OTP ciphers?
@VincentAdvocaat We will adapt; necessity is the mother of invention, especially when it comes to protecting sensitive information. Google for "post-quantum cryptography" if you're interested in learning more!
Apr
30
comment Why are there no OTP ciphers?
@VincentAdvocaat Smaller or equal in length to. And, yes, unfortunately. But fear not, modern cryptography has evolved past the OTP, your data can be made secure in practice! Just not unconditionally :-)
Apr
30
comment Why are there no OTP ciphers?
@VincentAdvocaat I have looked at your updated question. The answer is still no, for the same reason: if your key is $k$ bits long, there is no way to encrypt more than $k$ bits of data without losing unconditional security. Encrypt even a single bit more and the ciphertext begins leaking information about the plaintext (and hence the key) and the cipher is no longer unconditionally secure.
Apr
30
answered Why are there no OTP ciphers?
Apr
24
comment Prime factorization
@RickyDemer Prime powers work too