J.P. Morgan Chase & Co. Chief Executive James Dimon recently trashed the digital currency bitcoin as a fraud that will blow up. But he is still enamored with the technology that underpins it and other virtual currencies.

The latest sign came Monday, when the nation’s largest bank rolled out its next pilot program to use the record-keeping technology, known as blockchain. The initiative will enable the faster, more secure transfer of cross-border payments between J.P. Morgan, Royal Bank of Canada and Australia and New...