One of the main features intended for Bitcoin in the future is a native support for multisig payments and coinjoins, they are currently supported by the Blockchain but not in a native way and as such they do not have as much efficiency and privacy as desired. This is going to be the main focus of the next major update in Bitcoin, changing the signature scheme to Schnorr Signatures.

As a simplified alternative to Pay-to-Endpoint (P2EP - Pay-to-Endpoint), developer Ryan Havar proposed a BIP for a new coinjoins protocol that does not need changes to the current Bitcoin consensus and provides a simple, practical way to make coinjoin transactions that are indistinguishable from normal ones.

Alejandro Ranchal Pedrosa and Tucci-Piergiovanni proposed a new BIP to extend OP_CSV¹ and/or OP_CLTV² to allow and interpret negative values.

The discussion that followed concluded that the BIP would be breaking a fundamental rule which is that valid transactions remain valid. This could lead to loss of funds when several transactions are made invalid.

Multisig transactions ¹ have been a great use case of Bitcoin for the past few years, they require unsigned or partially signed transactions to be passed between multiple parties to “co-sign” them. However, there is currently no unified format for how multiple parties may share these transactions between multiple signers, it depends on the particular implementation for each wallet making it hard to do among parties using different Bitcoin wallets.

A draft BIP (174), which was proposed last year by Andrew Chow, was recently a subject of interest among Bitcoin developers. It aims to create a standard extensible format that different clients can implement making Partially Signed Bitcoin Transactions (PSBT) easier to pass around users to sign and combine their signatures.