Patent attributes
A computer-implemented exchange method is provided. The method may be performed on one or more blockchains, such as the Bitcoin Cash blockchain. The method comprises the steps of: communicating a first veiled secret value (H(A0)) from a first user to a second user and a second veiled secret value (H(B0) from the second user to the first user; and constructing first and second blockchain transactions (tx1, tx2) each comprising the first veiled secret value and the second veiled secret value, the transactions arranged to be unlockable to transfer control of a respective first or second resource upon provision of both the first secret value (A0) and the second secret value (B0) to the respective blockchain transaction, wherein unlocking of the first blockchain transaction causes a first secret value to be revealed to the second user, and unlocking of the second blockchain transaction causes a second secret value to be revealed to the first user.