A method and system of recording multiple transactions between a multiple of users on a blockchain (9), including a first transaction (22) from a first user (5) to a second user (7) and a second transaction (24) from the second user (7) to the first user (5). The blockchain may be, for example, the Bitcoin blockchain. The method may include receiving (110) a first request from a first node (15) associated with the first user (A) to transfer a first quantity of cryptocurrency associated with the first transaction (22) and receiving (120) a second request from a second node (17) to transfer a second quantity associated with the second transaction (24). The first transaction (22) is conditional on receiving (120) the second request and the second transaction (24) is conditional on receiving (110) the first request. The method also includes verifying (130) the first request and second request that includes determining both the conditional steps of receiving the first request and second request are satisfied. Based on verifying (130) the first request and second request, the method includes sending (140) a data output to the blockchain (9) to record the transfers of cryptocurrency associated with the first and second transactions (22, 24).