I must say, I have very limited knowledge on encryption, but, can't an observer possibly encrypt many possible and likely short messages (like, "hey!" or "lol") with the public keys of some users of value and sniff the network for matches? I mean it would take a while, maybe a week, to get some results but hey, I think it's a possibility.
can't an observer possibly encrypt many possible and likely short messages (like, "hey!" or "lol") with the public keys of some users of value and sniff the network for matches?
no. the same message does "never" encrypt to the same cypher:
It's a header with a version number and the ID of the receivers key that the message was encrypted with. Base64-decode and hexdump those messages and look for 54483646 (one of the subkeys of F8669BB7). The encrypted message is after that and would look random.
The format is defined in http://tools.ietf.org/html/rfc4880
edit: It's not encrypted with the primary key, but one of the subkeys.
Interesting, thanks for the overview. I'll have a poke around the doc :) I've been meaning to look into more about how these things work. I understand the very high level stuff and the very low level (how to use the tools roughly and some of the maths behind it all) but not so much in-between.
While cryptography does teach us that some methods are weak against such attacks, but since they are using asymmetric crypto, that means each of my messages would be encypted with the RECIPIENT's public key. thus you really dont know WHICH messages are encrypted with teh same key. thus you can't apply such an attack.
PS: i think asymmetric crypto is secure from such attacks anyways, though isn't that way slower than symmetric crypto?
