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Company description

Clef replaces usernames and passwords online. We recognize you by your smartphone instead of anything you have to remember or type to make logging in faster, safer, and much easier. 


The New York Times describes logging in with Clef as "magical" and with dozens of sites adding Clef login every day, the experience is spreading to more users every day. 


Passwords pit human memory against the brute force of computers — passwords can get longer and more complicated, but eventually we're going to lose. Clef wraps the security of public key cryptography in a mobile app that makes logging in fast and simple. Walk up to any computer and point your phone to be logged in instantly. 


After launching in June of 2013, it took 16 weeks to add the first 100 sites using Clef. By February, more than 1,000 sites were protecting their login with Clef, and by the end of March there were more than 2,400. 


The only security that matters is the security we use, and, traditionally, additional security slowed down user signups and return logins so marketing and growth teams fought to keep them out of products. Clef escapes the tradeoff in usability by letting a mobile device do all of the work — protecting sites from security breaches while actually increasing signups and retention.


Public key cryptography is used by engineers and security experts every day because it's the strongest way to identify yourself. Clef uses that same standard process, but makes it approachable and simple enough for anyone.


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  • Mark Hudnall
    Mark Hudnall | Founder
    Mark Hudnall is a co-founder and CTO of Clef, where he thinks about architecture and heads mobile development. Previously, he worked at Ning and Minted and studied computer science at Pomona College.
  • Jesse Pollak
    Jesse Pollak | Founder
    Jesse Pollak is one of the co-founders of Clef, where he runs all things prouduct. Previously, he was a hackNY fellow, worked at BuzzFeed, and dropped out of Pomona College.
  • B Byrne
    B Byrne | Founder
    B is the cofounder and CEO of Clef (, a replacement for usernames and passwords online. His focus is on making advanced technology accessible to anyone and applying it to everyday use cases.
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