CDMA (Code Division Multiple Access) is the digital telephone standard that was developed by Qualcomm and deployed by Sprint PCS and by Verizon. CDMA used RC4 encryption but the protocol doesn’t keep the keys secret, so in practice CDMA communications can be eavesdropped by a motivated attacker. In practice, though, it’s must easier to wiretap a CDMA telephone on the provider’s network. Today CDMA is used by the Sprint part of Sprint/Nextel and by Verizon.