Matrix has a detailed write up intended for client implementers: https://matrix.org/docs/matrix-concepts/end-to-end-encryption/ https://matrix.org/docs/matrix-c

Matrix has a detailed write up intended for client implementers: https://matrix.org/docs/matrix-concepts/end-to-end-encryption/ https://matrix.org/docs/matrix-concepts/end-to-end-encryptio... It should give you some ideas on how it's done.