Schlage’s contactless smart card readers are among the most secure readers in the industry. Instead of using open transmission protocols, Schlage smart card readers (formerly XceedID and aptiQ) utilize high security data. Each message between the card and reader is digitally signed using Message Authentication Coding (MAC) to ensure the integrity of the data. In addition to increased security, smart cards offer faster transaction times and greater data storage capacity. What differentiates smart cards from proximity cards is that the information can be read from or written to a credential.