> For the complete documentation index, see [llms.txt](https://docs.citrea.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.citrea.xyz/future-research/trustless-settlement.md).

# Trustless Settlement

In order to achieve trustless settlement for Citrea, there needs to be opcode change(s).

Mainly, an opcode that can verify ZK proofs and a [covenant opcode](https://covenants.info) would be required to implement completely trustless Bitcoin settlement. Specifically, it is theoretically possible to implement a trustless bridge using OP\_CAT opcode, if activated.

In the current architecture, BitVM/Clementine provides a trust-minimized settlement with 1-of-N honest minority trust assumption - which is a great improvement over the existing insecure implementations of sidechains. In case a suitable opcode is added to Bitcoin, Citrea will also adopt a cheaper/more secure/faster/trustless solution if possible.