Core Apps » PixelKnot

From Abel:
It appears [1] you are using standard AES-CBC to encrypt the message
contents before the stego process. AES-CBC is an unauthenticated form of
encryption. I don't see any code doing additional MACing of the
ciphertext, so Pixel Knot is vulnerable to active attackers flipping
bits as the messages travel on the wire.

I recommend switching to an authenticated encryption cipher mode,
namely, GCM.

If you're interested in Authenticated Encryption, Mathew Green's blog
post on this is super [2].

~abel

[1]:
https://github.com/guardianproject/PixelKnot/blob/master/src/info/guardianproject/pixelknot/crypto/Aes.java#L81

[2]:
http://blog.cryptographyengineering.com/2012/05/how-to-choose-authenticated-encryption.html