Authentication and Key Agreement (AKA) is a

security protocol A security protocol (cryptographic protocol or encryption protocol) is an abstract or concrete protocol that performs a security-related function and applies cryptographic methods, often as sequences of cryptographic primitives. A protocol descri ...

used in 3G networks. AKA is also used for

one-time password A one-time password (OTP), also known as a one-time PIN, one-time authorization code (OTAC) or dynamic password, is a password that is valid for only one login session or transaction, on a computer system or other digital device. OTPs avoid seve ...

generation mechanism for

digest access authentication Digest access authentication is one of the agreed-upon methods a web server can use to negotiate credentials, such as username or password, with a user's web browser. This can be used to confirm the identity of a user before sending sensitive infor ...

. AKA is a challenge–response based mechanism that uses

symmetric cryptography Symmetric-key algorithms are algorithms for cryptography that use the same cryptographic keys for both the encryption of plaintext and the decryption of ciphertext. The keys may be identical, or there may be a simple transformation to go between th ...

AKA in CDMA

AKA – Authentication and Key Agreement a.k.a. 3G Authentication, Enhanced Subscriber Authorization (ESA). The basis for the 3G authentication mechanism, defined as a successor to CAVE-based authentication, AKA provides procedures for

mutual authentication Mutual authentication or two-way authentication (not to be confused with two-factor authentication) refers to two parties authenticating each other at the same time in an authentication protocol. It is a default mode of authentication in some pro ...

of the Mobile Station ( 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 In cryptography, SHA-1 (Secure Hash Algorithm 1) is a cryptographically broken but still widely used hash function which takes an input and produces a 160-bit (20- byte) hash value known as a message digest – typically rendered as 40 hexadec ...

) *Support for mutual authentication *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 (also known as C2K or IMT Multi‑Carrier (IMT‑MC)) is a family of 3G mobile technology standards for sending voice, data, and Signaling (telecommunication), signaling data between mobile phones and cell sites. It is developed by 3GP ...

networks, although it is expected to be used for

IMS Ims is a Norwegian surname. Notable people with the surname include: * Gry Tofte Ims (born 1986), Norwegian footballer * Rolf Anker Ims (born 1958), Norwegian ecologist See also * IMS (disambiguation) Ims is a Norwegian surname. Notable people wit ...

. 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 The 3rd Generation Partnership Project 2 (3GPP2) is a collaboration between telecommunications associations to make a globally applicable third generation ( 3G) mobile phone system specification within the scope of the ITU's IMT-2000 project. In ...

X.S0006), which has been integrated into TIA-41 (3GPP2 X.S0004). For information on AKA in roaming, see CDG Reference Document #138.

AKA in UMTS

AKA a mechanism which performs authentication and session key distribution in

Universal Mobile Telecommunications System The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the In ...

(UMTS) networks. AKA is a challenge–response based mechanism that uses

. AKA is typically run in a UMTS

IP Multimedia Services Identity Module An IP Multimedia Services Identity Module (ISIM) is an application residing on the UICC, an IC card specified in TS 31.101. This module could be on a UMTS 3G or IMS VoLTE network. It contains parameters for identifying and authenticating the use ...

(ISIM), which is an application on a UICC (Universal Integrated Circuit Card). AKA is defined in RFC 3310.

Security

An attack against all variants of AKA has been reported, including 5G.

References

External links

Illustrated Master thesis of Authentication and Key Agreement (AKA) procedures and security aspects in UMTS
Cryptographic protocols Code division multiple access {{Authentication APIs