Johnson said that Discover and Barclaybank were "initial" participants, and refused to call them "exclusive" to Isis. While he noted Isis has been talking to all the major banks and credit card processors for months, he refused to confirm any others are involved.

Gartner analyst Mark Hung said that Citibank is widely known to be working with Isis, but Johnson said he couldn't confirm Citibank's involvement.

Isis' openness to other banks and credit card processors was part of the April press release, which focused on a Salt Lake City pilot of set for mid-2012, although the openness part was given less emphasis by Isis, as well as Computerworld and others' coverage.

Johnson said Isis decided last year to "go to market with fewer [companies] and ultimately the decision was to open to all payment networks." Ultimately, Isis could end up working with three or four banks and credit card processors, although not a much larger group, he predicted.

Johnson called the current state of Isis as an open mobile system an "acceleration" of its original mission and not a "dialing back" as depicted in the Journal article Wednesday. "We [Isis carriers] were never going to be the bank, and that may be an important clarification," Johnson said.