Privakey

Privakey’s mission is to simplify how people confirm their identities, assert their intent and respond to any challenge. Privakey works by turning users’ mobile phones into cryptographically-based, secure customer identifiers.  Customers using Privakey-enabled apps simply respond to challenges delivered to their phones with a message body that can contain any type of interactive digital content such as HTML, PDFs and forms.  Once the user has responded to a challenge, it is digitally signed and returned to the sender. To ensure a frictionless, but secure user experience, challenges can be configured to require a user to assert a biometric or PIN as a second factor of assurance.
Source:https://www.linkedin.com/company/privakey/about/