From b9e4cf53f5f0e6e10263aefcd2ad675a5ce2cb76 Mon Sep 17 00:00:00 2001 From: Brendan McMillion Date: Tue, 30 Jan 2024 08:23:12 -0800 Subject: [PATCH 1/2] Make encrypted group operation recommendation conditional. --- draft-ietf-mls-architecture.md | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/draft-ietf-mls-architecture.md b/draft-ietf-mls-architecture.md index 581e108..5c716d1 100644 --- a/draft-ietf-mls-architecture.md +++ b/draft-ietf-mls-architecture.md @@ -899,8 +899,8 @@ delivering messages asynchronously and reliably. ## Access Control Because all clients within a group (members) have access to the shared -cryptographic material, MLS protocol allows each member of the messaging group -to perform operations, However, every service/infrastructure has control over +cryptographic material, the MLS protocol allows each member of the messaging group +to perform operations. However, every service/infrastructure has control over policies applied to its own clients. Applications managing MLS clients can be configured to allow for specific group operations. On the one hand, an application could decide that a group administrator will be the only member to @@ -915,8 +915,10 @@ While the Application messages will always be encrypted, having the handshake messages in plaintext has privacy consequences as someone could collect the signatures on the handshake messages and use them for tracking. -> **RECOMMENDATION:** Prefer using encrypted group operation messages to avoid -> privacy issues related to non-encrypted signatures. +> **RECOMMENDATION:** Prefer using encrypted group operation messages unless a +> Delivery Service explicitly needs plaintext group operations to provide +> additional features. In this case, ensure that transport-layer encryption is +> always used. If handshake messages are encrypted, any access control policies must be applied at the client, so the application must ensure From 3b02ba48a879fa2947e8094eb12e44c41c603711 Mon Sep 17 00:00:00 2001 From: Benjamin Beurdouche Date: Thu, 7 Mar 2024 00:02:08 +0100 Subject: [PATCH 2/2] Update draft-ietf-mls-architecture.md Co-authored-by: raphaelrobert --- draft-ietf-mls-architecture.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/draft-ietf-mls-architecture.md b/draft-ietf-mls-architecture.md index 5c716d1..8750709 100644 --- a/draft-ietf-mls-architecture.md +++ b/draft-ietf-mls-architecture.md @@ -916,7 +916,7 @@ messages in plaintext has privacy consequences as someone could collect the signatures on the handshake messages and use them for tracking. > **RECOMMENDATION:** Prefer using encrypted group operation messages unless a -> Delivery Service explicitly needs plaintext group operations to provide +> Delivery Service explicitly needs plaintext handshake messages to provide > additional features. In this case, ensure that transport-layer encryption is > always used.