Digital identity authentication company Payfone has partnered with O2, a U.K.-based mobile network operator. The initiative aims to protect mobile users from digital fraud, including cyber-hacks, account takeover attacks, SIM swap attacks, and other forms of fraud.

The two are collaborating on Payfone’s Instant Authentication for Mobile, a behind-the-scenes, identity verification solution that enables enterprises to authenticate their clients quickly and securely by using a Trust Score that is generated by analyzing millions of digital signals against multiple authentication factors. One of those factors is real-time authentication from O2, which relies on a mobile phone and does not require the user to switch between channels, such as in two-factor authentication.

Payfone CEO Rodger Desai said, “Payfone is already on track to authenticate 50,000,000 transactions per day in the United States, and extending our capabilities into the United Kingdom is a major milestone for us as we continue our expansion into 35 worldwide markets.”

Originally a mobile payments company, Payfone was founded in 2008. The New York-based company has since pivoted to focus on authentication solutions, adopting the motto, “Delight users. Defeat hackers.” Payfone, whose technologies are currently used by six of the top 10 U.S. banks, processes millions of signals per day to authenticate and score transactions; the company currently authenticates 10 million transactions per day. Last spring, Payfone announced it would power mobile ID authentication for Zelle.

There’s been a lot of hype around real-time P2P payment app Zelle, which is launching at select banks this month, aiming to take on Venmo and PayPal as the leading P2P payment platform. Facilitating the launch, Zelle has tapped New York-based Payfone as a key partner.

Payfone signed an agreement with Early Warning Systems, the parent company of Zelle (formerly clearXchange), which was launched in 2011 in a joint effort among Bank of America, Capital One, JP Morgan Chase, U.S. Bank and Wells Fargo. Under the agreement, Zelle will leverage Payfone’s mobile identity authentication and risk assessment solutions to streamline client enrollment and authentication for transactions.

Rodger Desai, Payfone CEO, said that the company is “uniquely positioned” to provide “instant mobile authentication,” something he described as a crucial element in faster payments. Desai added, “Collaborating with Early Warning to help add further seamless security to Zelle is a shining example of how Payfone makes customer transactions safer and smoother.”

Eric Woodward, group president of the Risk Solutions business at Early Warning, said that Payfone will “significantly simplify” enrollment for new Zelle users via a “non-intrusive” user experience. “This helps us balance the requirements for speed and security in the faster payments space,” Woodward said.

Founded in 2008, Payfone originated as a mobile payments company. It has since pivoted to focus on authentication solutions, processing millions of signals per day to authenticate and score transactions with its new Lotus Trust Score. The company currently authenticates 10 million transactions per day and by year end it anticipates that number will reach 50 million transactions.