From 25a2e3463ecc0fceb2677deda5f9456c445bd559 Mon Sep 17 00:00:00 2001 From: Alex Stokes Date: Tue, 8 Jun 2021 12:06:02 -0700 Subject: [PATCH] Update specs/altair/p2p-interface.md Co-authored-by: Diederik Loerakker --- specs/altair/p2p-interface.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/specs/altair/p2p-interface.md b/specs/altair/p2p-interface.md index 49082452f..4021cbbd0 100644 --- a/specs/altair/p2p-interface.md +++ b/specs/altair/p2p-interface.md @@ -74,7 +74,7 @@ New topics are added in Altair to support the sync committees and the beacon blo The specification around the creation, validation, and dissemination of messages has not changed from the Phase 0 document. -The derivation of the `message-id` has changed starting with Altair to incorporate the message topic along with the message data. +The derivation of the `message-id` has changed starting with Altair to incorporate the message `topic` along with the message `data`. These are fields of the `Message` Protobuf, and interpreted as empty byte strings if missing. The `message-id` MUST be the following 20 byte value computed from the message: * If `message.data` has a valid snappy decompression, set `message-id` to the first 20 bytes of the `SHA256` hash of the concatenation of `MESSAGE_DOMAIN_VALID_SNAPPY` with the snappy decompressed message data and the topic name,