AKA stands for the Authentication and Key Agreement. It is a security protocol used in 3G

3G

3G or 3rd generation mobile telecommunications is a generation of standards for mobile phones and mobile telecommunication services fulfilling the International Mobile Telecommunications-2000 specifications by the International Telecommunication Union...

 networks.
AKA is also used for one-time password generation mechanism for Digest

Digest access authentication

Digest access authentication is one of the agreed upon methods a web server can use to negotiate credentials with a user's web browser. It uses encryption to send the password over the network which is safer than the Basic access authentication that sends plaintext.Technically digest...

 access authentication

Authentication

Authentication is the act of confirming the truth of an attribute of a datum or entity...

. AKA is a challenge-response based mechanism that uses symmetric cryptography.

AKA in CDMA

AKA – Authentication and Key Agreement
a.k.a. 3G Authentication, Enhanced Subscriber Auth. (ESA)

The basis for the 3G authentication mechanism defined as a successor to CAVE-based Authentication

CAVE-based Authentication

CAVE-based Authentication is an access authentication used in CDMA/1xRTT network systems.-CAVE :gtv...

. AKA provides procedures for mutual authentication

Mutual authentication

Mutual authentication or two-way authentication refers to two parties authenticating each other suitably. In technology terms, it refers to a client or user authenticating themselves to a server and that server authenticating itself to the user in such a way that both parties are assured of the...

 of the MS and serving system. The successful execution of AKA results in the establishment of a security association (i.e., set of security data) between the MS and serving system that enables a set of security services to be provided.

Major advantages of AKA over CAVE-based authentication include:

• Larger authentication keys (128-bit )
• Stronger hash function (SHA-1)
• Support for mutual authentication
  Mutual authentication
  Mutual authentication or two-way authentication refers to two parties authenticating each other suitably. In technology terms, it refers to a client or user authenticating themselves to a server and that server authenticating itself to the user in such a way that both parties are assured of the...
  
  
• Support for signaling message data integrity
• Support for signaling information encryption
• Support for user data encryption
• Protection from rogue MS when dealing with R-UIM

AKA is not yet implemented in CDMA2000

CDMA2000

CDMA2000 is a family of 3G mobile technology standards, which use CDMA channel access, to send voice, data, and signaling data between mobile phones and cell sites. The set of standards includes: CDMA2000 1X, CDMA2000 EV-DO Rev. 0, CDMA2000 EV-DO Rev. A, and CDMA2000 EV-DO Rev. B...

 networks, although it is expected to be used for IMS

IP Multimedia Subsystem

The IP Multimedia Subsystem or IP Multimedia Core Network Subsystem is an architectural framework for delivering Internet Protocol multimedia services. It was originally designed by the wireless standards body 3rd Generation Partnership Project , as a part of the vision for evolving mobile...

. To ensure interoperability with current devices and partner networks, support for AKA in CDMA networks and handsets will likely be in addition to CAVE-based authentication.

Air interface support for AKA is included in all releases following CDMA2000 Rev C.

TIA-41 MAP support for AKA was defined in TIA-945 (3GPP2 X.S0006), which has been integrated into TIA-41 (3GPP2 X.S0004).

For information on AKA in roaming, see CDG

CDG

CDG may refer to:* IATA code for Charles de Gaulle Airport, in Paris, France* Congenital disorder of glycosylation also known as "CDG Syndrome"* Costume Designers Guild...

 Reference Document #138.

AKA in UMTS

AKA is a mechanism which performs authentication and session key distribution in Universal Mobile Telecommunications System

Universal Mobile Telecommunications System

Universal Mobile Telecommunications System is a third generation mobile cellular technology for networks based on the GSM standard. Developed by the 3GPP , UMTS is a component of the International Telecommunications Union IMT-2000 standard set and compares with the CDMA2000 standard set for...

 (UMTS) networks. AKA is a challenge-response based mechanism that uses symmetric cryptography. AKA is typically run in a UMTS IP Multimedia Services Identity Module (ISIM

ISIM

An IP Multimedia Services Identity Module is an application running on a UICC smart card in a 3G mobile telephone in the IP Multimedia Subsystem . It contains parameters for identifying and authenticating the user to the IMS...

), which resides on a smart card

Smart card

A smart card, chip card, or integrated circuit card , is any pocket-sized card with embedded integrated circuits. A smart card or microprocessor cards contain volatile memory and microprocessor components. The card is made of plastic, generally polyvinyl chloride, but sometimes acrylonitrile...

 like device that also provides tamper resistant storage of shared secrets. AKA is defined in RFC 3310.

AKA in WiMAX

AKA is also specified for WiMAX

WiMAX

WiMAX is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. The 2005 WiMAX revision provided bit rates up to 40 Mbit/s with the 2011 update up to 1 Gbit/s for fixed stations...

 (IEEE 802.16m), based on the Extensible Authentication Protocol

Extensible Authentication Protocol

Extensible Authentication Protocol, or EAP, is an authentication framework frequently used in wireless networks and Point-to-Point connections. It is defined in RFC 3748, which made RFC 2284 obsolete, and was updated by RFC 5247....

(EAP).