> variable bitrate encoding
I hope not... VBR can easily leak all sorts of information (including the actual content of the conversation)
I hope not... VBR can easily leak all sorts of information (including the actual content of the conversation)
Do you have a link discussing this?
https://www.cs.jhu.edu/~cwright/oakland08.pdf
https://www.cs.jhu.edu/~cwright/voip-vbr.pdf
It's fundamentally very similar to the sorts of issues you end up with if you compress then encrypt. If the attacker can make some educated guesses about the plaintext prior to the compression, the compression ratio can be a very powerful tool in their arsenal.