On Sun, Dec 11, 2016 at 4:30 PM, Andrew Lunn <and...@lunn.ch> wrote: > I'm not a crypto expert, but does this not give you a helping hand in > breaking the crypto? You know the plain text value of these bytes, and > where they are in the encrypted text.
You also know with some probability that there's going to be an IP header and a TCP header, each with predictable fields. Maybe you're reasonably certain there's an HTTP header in there too. Gasp! But fear not... Symmetric ciphers are generally not considered secure if they fall to what's called a "known plaintext attack". Fortunately, modern ciphers like AES and ChaCha20 and most others that you're aware of are generally believed to be secure against KPA.
