Over the past few hours, some Keychat users may have noticed several strange messages like the one shown in the screenshot — “null invalid HMACtrack: decrypt failed” — when sending messages in a large group.

Our current suspicion is that someone was spamming NIP-17 messages to the receiving address subscribed to by the large group. Those messages were received by the group, but failed during decryption, which led to the error shown in the screenshot.