Originally introduced in 1.19.1, chat reporting has undergone many changes in Mojang's attempts to eliminate the exploits and make the system functional. The purpose of this paper is to document the current technical state of chat reporting on an ongoing basis, and to provide a reference for the community to use when discussing the system. To that end I will try to keep it as unbiased as possible.
Chat reporting heavily relies on cryptographic commitments and signatures to ensure that reported chat messages are not tampered with. The basic idea is that all players sign their chat messages with their private key, and then send the signature along with the message to the server.
Chat signing keypair is not generated by the client as one could expect; instead, it is issued by Mojang's services and is tied to the player's account. This means that the keypair is shared between all clients that the player uses, and the player can't change it. The keypair is f