diff --git a/draft-ietf-mls-architecture.md b/draft-ietf-mls-architecture.md index 064fe26..d5a6f7d 100644 --- a/draft-ietf-mls-architecture.md +++ b/draft-ietf-mls-architecture.md @@ -1418,12 +1418,13 @@ MLS provides additional protection regarding secrecy of past messages and future messages. These cryptographic security properties are Forward Secrecy (FS) and Post-Compromise Security (PCS). -FS means that access to all encrypted traffic history combined with access to -all current keying material on clients will not defeat the secrecy properties of -messages older than the oldest key of the compromised client. Note that this -means that clients have the extremely important role of deleting appropriate -keys as soon as they have been used with the expected message, otherwise the -secrecy of the messages and the security for MLS is considerably weakened. +FS means that access to all encrypted traffic history combined with +access to all current keying material on clients will not defeat the +secrecy properties of messages older than the oldest key of the +compromised client. Note that this means that clients the appropriate +keys as soon as they have been used with the expected message, +otherwise the secrecy of the messages and the security for MLS is +considerably weakened. PCS means that if a group member's state is compromised at some time t1 but the group member subsequently performs an update at some time t2, then all MLS @@ -1967,7 +1968,7 @@ and identities. If the signature keys are reused across groups, the adversary can get more information about the targeted user. > **RECOMMENDATION:** Ensure that linking between public keys and identities -> only happens in expected scenarios. Otherwise privilege a stronger separation. +> only happens in expected scenarios. ## Considerations for attacks outside of the threat model