Editing ISO/IEC 7816 (section)

== 7816-4: Organization, security and commands for interchange ==

This part describes the [[Smart card application protocol data unit|smart card APDU protocol]] used by many smart card and contactless devices, like [[EMV]] payment cards, and forms the basis of [[CCID (protocol)|CCID protocol]] for [[Security token|security token]] devices. Many devices operate within the proprietary part of the protocol, using the standardized part for establishing the initial communication before switching to application specific exchange of data.

Created in 1995, updated in 2005, 2013 and 2020.<ref>{{cite web|url=https://www.iso.org/standard/77180.html |title=ISO/IEC 7816-4:2020 Identification cards — Integrated circuit cards — Part 4: Organization, security and commands for interchange |publisher=Iso.org |date=May 2020 |access-date=2020-08-05}}</ref> Amended in 2023.<ref>{{cite web |title=ISO/IEC 7816-4:2020/Amd 1:2023 Identification cards — Integrated circuit cards — Part 4: Organization, security and commands for interchange  —  Amendment 1: Support of multiple logical security devices |url=https://www.iso.org/standard/84943.html |publisher=Iso.org |access-date=2023-05-08 |date=2023-10-01}}</ref>

According to its abstract, it specifies:
* contents of command-response pairs exchanged at the interface,
* means of retrieval of data elements and data objects in the card,
* structures and contents of historical bytes to describe operating characteristics of the card,
* structures for applications and data in the card, as seen at the interface when processing commands,
* access methods to files and data in the card,
* a security architecture defining access rights to files and data in the card,
* means and mechanisms for identifying and addressing applications in the card,
* methods for secure messaging,
* access methods to the algorithms processed by the card. It does not describe these algorithms.

It does not cover the internal implementation within the card or the outside world.

ISO/IEC 7816-4:2020 is independent of the physical interface technology, and applies equally to contact cards, [[proximity card]]s and [[vicinity card]]s.