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Questions - block-cipher

What [uint64 x1 = *(const uint64*)in;] and [uint64 x2 = *(((const uint64*)in)+1);] mean in Kuznyechik source code (from VeraCrypt ciphers)

There are two elements in Kuznyechik source code from VeraCrypt source code: https://github.com/veracrypt/VeraCrypt/blob/master/src/Crypto/kuznyechik.c#L2271-L2272 uint64 x1 = *(const uint64*)in; uint...
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phantomcraft

c

variables

block-cipher

veracrypt

Votes: 0

Answers: 1

Latest Answer

Looking at somewhat more of the code than what you posted, I see that in is a function parameter declared as (a typedef for) const char *. Given that, the first fragment you posted could have been wr...
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zwol

Purpose of EVP_EncryptFinal_ex function in OpenSSL

I'm trying to implement AES symmetric encryption using the OpenSSL library. In the encryption examples, after calling the EVP_EncryptUpdate function, the EVP_EncryptFinal_ex function is immediately ca...
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John

c++

encryption

openssl

aes

block-cipher

Votes: 0

Answers: 1

Latest Answer

This is strangely only explained in the API documentation of EVP_EncryptUpdate(): If padding is enabled (the default) then EVP_EncryptFinal_ex() encrypts the "final" data, that is any data ...
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Maarten Bodewes - on strike

What would be faster: Spliting a 64-bit word into 16 nibbles and entering them in S-Boxes or using an entire 64-bit word directly as an entry?

This question is related to cryptography, but I believe I'm asking in right place (not in Crypto Stackexchange). Kuznyechik block cipher splits a 64-bit word into 16 nibbles (4-bits) and use them as e...
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phantomcraft

performance

cpu-word

block-cipher

cpu-cycles

nibble

Votes: 0

Answers: 0

What is the SWAPMOVE function in block cipher?

I saw a function called 'SWAPMOVE' below. SWAPMOVE(A,B,M,n): T = (B ^ (A >> n)) & M B = B ^ T A = A ^ (T << n) And I don't know what does this function actually do. It see...
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Serenity

function

cryptography

bitwise-operators

block-cipher

Votes: 0

Answers: 2

Latest Answer

Let's look at this in some more detail. Pretend we didn't have M, which is a mask. In such a case, B = B ^ T would be equivalent to B = B ^ B ^ (A >> n). That would itself be equivalent to B =...
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bk2204

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