Editing Smart card (section)

== Design ==
A smart card may have the following generic characteristics:

* Dimensions similar to those of a credit card. ID-1 of the [[ISO/IEC 7810]] standard defines cards as nominally {{convert|85.60|x|53.98|mm|sigfig=3}}. Another popular size is ID-000, which is nominally {{convert|25|x|15|mm}} (commonly used in SIM cards). Both are {{convert|0.76|mm}} thick.
* Contains a [[tamper-resistant]] security system (for example a [[secure cryptoprocessor]] and a secure [[file system]]) and provides security services (e.g., protects in-memory information).
* Managed by an administration system, which securely interchanges information and configuration settings with the card, controlling card [[Blacklist (computing)|blacklisting]] and application-data updates.
* Communicates with external services through card-reading devices, such as ticket readers, [[Automated teller machine|ATM]]s, [[Dip reader]], etc.
* Smart cards are typically made of plastic, generally [[polyvinyl chloride]], but sometimes [[polyethylene terephthalate|polyethylene-terephthalate]]-based [[polyesters]], [[acrylonitrile butadiene styrene]] or [[polycarbonate]].
Since April 2009, a Japanese company has manufactured reusable financial smart cards made from paper.<ref>{{cite news|title=development of the "KAMICARD" IC card made from recyclable and biodegradable paper|url=http://www.toppan.co.jp/english/news/newsrelease883.html|archive-url=https://web.archive.org/web/20090227010101/http://www.toppan.co.jp/english/news/newsrelease883.html|publisher=Toppan Printing Company|archive-date=27 February 2009|url-status=dead|access-date=27 March 2009}}</ref>

=== Internal structure ===
==== Data structures ====
As mentioned above, data on a smart card may be stored in a [[file system]] (FS). In smart card file systems, the root directory is called the "master file" ("MF"), subdirectories are called "dedicated files" ("DF"), and ordinary files are called "elementary files" ("EF").<ref name="kilicli-howto">{{cite web|first1=Tolga|last1=Kiliçli|title=Smart Card HOWTO|url=http://linux.com/learn/docs/ldp/750-Smart-Card-HOWTO|archive-url=https://web.archive.org/web/20090615092131/http://linux.com/learn/docs/ldp/750-Smart-Card-HOWTO|date=19 September 2001|archive-date=15 June 2009|access-date=28 November 2020|url-status=dead}}</ref>

==== Logical layout ====
The file system mentioned above is stored on an [[EEPROM]] (storage or memory) within the smartcard.<ref name="kilicli-howto"/> In addition to the EEPROM, other components may be present, depending upon the kind of smartcard. Most smartcards have one of three logical layouts:

* [[EEPROM]] only.
* EEPROM, ROM, RAM, and microprocessor.
* EEPROM, ROM, RAM, microprocessor, and [[secure element]].<ref name="kilicli-howto"/>

In cards with microprocessors, the microprocessor sits inline between the reader and the other components. The operating system that runs on the microprocessor mediates the reader's access to those components to prevent unauthorized access.<ref name="kilicli-howto"/>

=== Physical interfaces ===
==== Contact smart cards ====
[[File:Smartcard chip structure and packaging EN.svg|thumb|Illustration of smart-card structure and packaging]]
[[File:Sim Chip.jpg|thumb|4 by 4 mm silicon chip in a SIM card, which was peeled open. Note the thin gold bonding wires and the regular, rectangular digital-memory areas.]]
[[File:SmartCardPinout.svg|thumb|A smart-card [[pinout]]. '''VCC''': [[IC power supply pin|Power supply]]. '''RST''': Reset signal, used to reset the card's communications. '''CLK''': Provides the card with a [[clock signal]], from which data communications timing is derived. '''GND''': [[Ground (electricity)|Ground]] (reference voltage). '''VPP''': ISO/IEC 7816-3:1997 designated this as a programming voltage: an input for a higher voltage to program persistent memory (e.g., [[EEPROM]]). ISO/IEC 7816-3:2006 designates it SPU, for either standard or proprietary use, as input and/or output. '''I/O''': Serial input and output ([[half-duplex]]). '''C4, C8''': The two remaining contacts are AUX1 and AUX2 respectively and are used for [[USB]] interfaces and other uses.<ref>[http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?csnumber=36576 ISO/IEC 7816-2:1999/Amd 1:2004 ''Assignment of contacts C4 and C8''] {{Webarchive|url=https://web.archive.org/web/20120315031835/http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?csnumber=36576 |date=15 March 2012 }}.</ref> However, the usage defined in ISO/IEC 7816-2:1999/Amd 1:2004 may have been superseded by ISO/IEC 7816-2:2007.<ref>[http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=45989 ISO/IEC 7816-2:2007. Identification cards – Integrated circuit cards – Part 2: Cards with contacts – Dimensions and location of the contacts] {{Webarchive|url=https://web.archive.org/web/20160304093036/http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=45989 |date=4 March 2016 }}.</ref>]]

[[File:Differentsmartcardpadlayouts.jpg|thumb|Contact-type smart cards may have many different [[contact pad]] layouts, such as these [[Subscriber identity module|SIMs]].]]
Contact smart cards have a contact area of approximately {{convert|1|cm2}}, comprising several gold-plated [[contact pad]]s. These pads provide electrical connectivity when inserted into a [[Card reader|reader]],<ref>{{cite web|title=About Smart Cards: Introduction: Primer|url=http://www.smartcardalliance.org/smart-cards-intro-primer/|publisher=Secure Technology Alliance|access-date=7 August 2017|archive-date=27 March 2018|archive-url=https://web.archive.org/web/20180327135443/http://www.smartcardalliance.org/smart-cards-intro-primer/|url-status=live}}</ref> which is used as a communications medium between the smart card and a host (e.g., a computer, a point of sale terminal) or a mobile telephone. Cards do not contain [[Battery (electricity)|batteries]]; power is supplied by the card reader.

The [[ISO/IEC 7810]] and [[ISO/IEC 7816]] series of standards define:
* physical shape and characteristics,
* electrical connector positions and shapes,
* electrical characteristics,
* [[communications protocol]]s, including commands sent to and responses from the card,
* basic functionality.

Because the chips in financial cards are the same as those used in [[subscriber identity module]]s (SIMs) in mobile phones, programmed differently and embedded in a different piece of [[Polyvinyl chloride|PVC]], chip manufacturers are building to the more demanding GSM/3G standards. So, for example, although the EMV standard allows a chip card to draw 50&nbsp;mA from its terminal, cards are normally well below the telephone industry's 6&nbsp;mA limit. This allows smaller and cheaper financial card terminals.

Communication protocols for contact smart cards include T=0 (character-level transmission protocol, defined in ISO/IEC 7816-3) and T=1 (block-level transmission protocol, defined in ISO/IEC 7816-3).

==== Contactless smart cards ====
{{Main|Contactless smart card}}

''Contactless smart cards'' communicate with readers under protocols defined in the [[ISO/IEC 14443]] standard. They support data rates of 106–848&nbsp;kbit/s. These cards require only proximity to an antenna to communicate.
Like smart cards with contacts, contactless cards do not have an internal power source. Instead, they use a [[loop antenna]] coil to capture some of the incident radio-frequency interrogation signal, [[rectifier|rectify]] it, and use it to power the card's electronics. Contactless smart media can be made with PVC, paper/card and PET finish to meet different performance, cost and durability requirements.

APDU transmission by a contactless interface is defined in [[ISO/IEC 14443]]-4.

==== Hybrids ====
[[File:Australia Bank Paypass Card.png|thumb|A hybrid smart card, which clearly shows the antenna connected to the main chip]]

Hybrid cards implement contactless and contact interfaces on a single card with unconnected chips including dedicated modules/storage and processing.

;Dual-interface

Dual-interface cards implement contactless and contact interfaces on a single chip with some shared storage and processing. An example is [[Porto]]'s multi-application transport card, called [[Andante ticket|Andante]], which uses a chip with both contact and [[Contactless smart card|contactless]] (ISO/IEC 14443 Type B) interfaces. Numerous payment cards worldwide are based on hybrid card technology allowing them to communicate in contactless as well as contact modes.

====USB====
The [[CCID (protocol)|CCID]] (Chip Card Interface Device) is a USB protocol that allows a smart card to be interfaced to a computer using a card reader which has a standard USB interface. This allows the smart card to be used as a security token for authentication and data encryption such as [[Bitlocker]]. A typical CCID is a USB dongle and may contain a SIM.

===Logical interfaces===
====Reader side====
Different smart cards implement one or more reader-side protocols. Common protocols here include CT-API and [[PC/SC]].<ref name="kilicli-howto"/>

====Application side====
Smartcard operating systems may provide application programming interfaces (APIs) so that developers can write programs ("applications") to run on the smartcard. Some such APIs, such as [[Java Card]], allow programs to be uploaded to the card without replacing the card's entire operating system.<ref name="kilicli-howto"/>