US Patent 11301844 Cryptographic authentication and tokenized transactions

A cryptographic method of performing a tokenised transaction between a payment offering party and a payment accepting party is described. The tokenised transaction is mediated by a transaction scheme. The payment accepting party is provided with a merchant identity and a merchant certificate associated with that identity by the transaction scheme provider. The payment accepting party provides the merchant identity and transaction seed data to the payment offering party. The payment offering party validates the merchant identity and uses the merchant identity and the transaction seed data to generate a cryptogram for the tokenised transaction. The payment offering party provides the cryptogram to the payment accepting party for transmission to the transaction scheme provider for authorisation of the tokenised transaction. A suitable user computing device and merchant computing device for acting as payment offering party and payment accepting party respectively are also described.