The invention provides a novel and advantageous method and corresponding system. The invention is implemented via a distributed electronic ledge (blockchain). This may or may not be the Bitcoin blockchain. The invention is suited for the exchange or transfer of an asset, e.g. a digital asset, such as tickets and the like (but not limited in this regard). A n embodiment may provide a computer - implemented method for transferring an asset between a first user and a second user via a blockchain, the method comprising: generating a first blockchain transaction comprising at least one first output, representing at least one first asset, redeemable by providing either: (i) unlocking data; or (ii) a cryptographic signature of the first user and a cryptographic signature of a second user, wherein the at least one first asset is exchanged for at least one second asset represented by a t least one second output of a second blockchain transaction, the at least one second output redeemable by providing either: (i) the unlocking data; or (ii) the cry ptographic signature of the first user and the cryptographic signature of the second user, and wherein redemption of at least one second output by providing the first unlocking data makes the first unlocking data available to redeem at least one first output. The unlocking data may the unlocking data comprise revealable data which is chosen by the first user and is initially kept secret or unknown to the second user. Redemption of a third transaction causes the revealable data to become publicly available via the blockchain and thus known to the second user, who can use it in another unlocking script.