Multifactor authentication is one of the most reliable ways to combat account hijacking, but it’s typically applied in a fairly rigid way that requires users to perform the same verification steps regardless of the circumstances. London’s Callsign Ltd. today said it has secured a $35 million investment led by Accel and early-stage fund PTB Ventures to help companies implement a more flexible approach.

The startup offers a platform that can customize the authentication process on a case-by-case basis. When a user first signs up for a service protected by Callsign, its algorithms will start collecting information about their location, device preferences and roughly 50 other metrics. This information is correlated with high-level data from the other accounts that the startup monitors to create an activity profile that serves as a reference against which future login attempts are checked.

Once Callsign has learned enough about a user, they’ll begin seeing changes in how they’re vetted. The startup’s platform fine-tunes the number and type of authentication steps required to sign in based on how well an access attempt lines up with past behavior.

If workers try to sign into their company’s accounting system on unrecognized devices, Callsign platform may ask them to answer an extra security question or perform voice verification. On the other hand, accessing the same system from a trusted workstation in the office might lead its algorithms to waive the need for login credentials altogether. Callsign offers a mobile client that lets users to confirm their identity using a simple swipe when the perceived risk is low.

The startup said its platform thus makes it possible to achieve an optimal balance between security and convenience. Companies can save trusted users the trouble of performing multifactor authentication, while taking extra security measures when there’s reason for suspicion.

The end result is a major reduction in the risk of account breaches. According to TechCrunch, Callsign’s platform is used by major financial institutions such as Lloyds Banking Group plc and Deutsche Bank AG to protect hundreds of thousands of users.

Today’s funding is aimed at helping the British startup further expand its reach. Callsign initially intends to focus on geographic expansion, a push that is set to see the launch of new offices in New York and the Bay Area over the coming months. It also has plans to start targeting organizations in Asia further down the road.

Image: Callsign