cryptography - should you authenticate the initialization vector in ipsec? -
i'm trying implement ipsec in form of esp in transport mode using aes in galois/counter mode, according rfc4106.
i'm supposed put initialization vector before ciphertext in transformed packet.
should part of authenticated (but non-encrypted) data? (i'm assuming don't encrypt it...)
i can't see rfc specifies this. should obvious , if why?
as far understand gcm definition, there no need include initialization vector in associated data - using different initialization vectors give both different encryption results different integrity check value anyway.
this advantage of using combined authenticated-encryption mode, don't have care including initialization vectors in mac.
so, encode packet esp gcm, this:
- fetch key
- generate iv
- calculate associated data (from spi , sequence number)
- get plaintext
- pass iv, associated data, key, plaintext gcm algorithm
- get ciphertext , icv gcm algorithm
- send iv, ciphertext , icv
Comments
Post a Comment