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9 votes

Calculating 3DES Key Check Value (KCV)

Three problems here: The online tool used expects a 24-byte (48 hex-character) key; thus you should enter E6F1081FEA4C402CC192B65DE367EC3EE6F1081FEA4C402C as the ...
fgrieu's user avatar
  • 141k
7 votes

Can an authenticated encryption scheme detect if wrong key is used?

This is an interesting question, and it depends on the situation where you might decrypt with the "wrong" key. If two keys $k_1$ and $k_2$ are independently generated, and $c$ is an honestly ...
Mikero's user avatar
  • 13.3k
4 votes

Risks of full length KCV (components and full keys)?

The usual (or at least traditional) blockcipher KCV is not a hash but rather the truncated encryption of zero; see How to obtain KCV from the key and KCV and compatibility with block cipher modes of ...
dave_thompson_085's user avatar
2 votes
Accepted

Calculating 3DES Key Check Value (KCV)

I just put together a tiny python (python 3) example that calculates the KCV that PC Crypto is issuing (first 4 bytes of the encryption of binary 0's with the key portion). I can confirm that the ...
neif's user avatar
  • 181
2 votes
Accepted

Is it safe to use the CBC-MAC as a Initial Vector and Key Check Value in deterministic encryption?

Am I thinking correctly and will an malicious user (which has access to encryption keys) not (or very hard) be able to generate a collision in my IV-ciphertext combination so that the server is ...
poncho's user avatar
  • 147k
2 votes

Discrepancy between 3DES in OpenSSL and PyDES

In Python and on that website, you're entering a key. A 3-DES key consists of 24 bytes. You picked a key that's some nice printable text, but a key in general is binary, randomly generated. With the ...
Gilles 'SO- stop being evil''s user avatar
1 vote

Will two KEK's provide the same KCV or should these be different?

The KCV generally consists of a single encryption of a block of all zeros using the key itself - and then taking a number of leftmost bytes, usually displayed as hexadecimals. That means that the KCV ...
Maarten Bodewes's user avatar
  • 92.7k

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