diff options
author | 2016-01-28 16:34:05 -0800 | |
---|---|---|
committer | 2016-01-28 16:34:05 -0800 | |
commit | c4faed7b098b0b0b4f08bedb1940c770a77f3746 (patch) | |
tree | 520feb21053aad80e232db57903409ca5880506a | |
parent | Some edits to ID hiding and validity (diff) | |
download | noise-c4faed7b098b0b0b4f08bedb1940c770a77f3746.tar.xz noise-c4faed7b098b0b0b4f08bedb1940c770a77f3746.zip |
7.1 validity edits
-rw-r--r-- | noise.md | 21 |
1 files changed, 9 insertions, 12 deletions
@@ -538,21 +538,18 @@ Noise patterns must be **valid** in the following senses: keys they possess. * Parties must send an ephemeral public key as the first token of the first - message they send in a handshake pattern. This is because Noise requires DH - outputs involving ephemeral keys to randomize the shared secret keys, and - also uses ephemeral public keys as random PSK nonces. + message they send. * Parties must not send static public keys and payloads, nor complete the handshake, unless they have performed DH between their current ephemeral - and all of the other party's current key pairs. This provides good forward - secrecy and authentication. This also prevents subtle attacks where an - invalid public key could be used to force a DH output to a constant value - (e.g. zero), thus nullifying the randomizing effect of one party's - ephemeral, and triggering catastrophic reuse of a `"dhss"`-derived key. - -Patterns failing the first check will obviously abort the program. Patterns -failing the second and third checks could result in subtle but catastrophic -security flaws. + and all of the other party's current key pairs that they are aware of. + +Patterns failing the first check will obviously abort the program. + +The second and third checks are necessary because Noise requires DH outputs +involving ephemeral keys to randomize the shared secret keys, and also uses +ephemeral public keys as random PSK nonces. Patterns failing these checks +could result in subtle but catastrophic security flaws. 7.2. One-way patterns ---------------------- |