A method includes receiving, by a loan program executing on a loan computing system, conditions from an originator program executing on an originator computing system. The conditions are sent, by the loan program, to a wallet program executing on a wallet computing system. Cryptographic proof that the conditions are met is received by the loan program from the wallet program. Ownership data of the loan program is updated by the loan program to identify a buyer program executing on a buyer computing system in response to invocation of a purchase function of the loan program. Payment receipt data is appended, by the loan program, to the loan program in response to invocation of a payment append function of the loan program by a loan service program executing on a loan service computing system.