Heartland Payment Systems Inc. says its E3 encryption system has been adopted by several payment hardware makers.

The Princeton, N.J., processor said the E3 protocol specification, which supports card data encryption from the point the card is swiped, has been provided to Uniform Industrial Corp., Hypercom Corp., ExaDigm Inc. and other terminal manufacturers.

"As several of the world's leading payments equipment manufacturers move to embrace our E3 protocol, it is a testament to the security, innovation and interoperability of our solution," Steve Elefant, Heartland's chief information officer, said in a press release.

Heartland began testing the E3 system in June and now offers it in limited release. It said it plans to offer E3 in wide release in the second quarter.