Since the turn of the century, smart card technology has pushed its borders both on the high end to integrate new functionalities (e.g., networking) and on the low end to adapt to new constrained environments (e.g., radio-frequency identification). This has required changes in the hardware, software and cryptography underpinning smart cards. This special issue covers some of these developments in depth. Ó 2007 Elsevier B.V. All rights reserved.