Security algorithms

An encryption algorithm is a mathematical procedure used to encrypt data. Through the use of an algorithm and a key, information is encoded into cipher text and requires the use of a 'key' to transform the data back into its original form.

Algorithms are an essential part of a technology to ensure effective and secure authentication, as well as to provide integrity and encryption. ETSI creates cryptographic algorithms and protocols specific to fraud prevention, unauthorized access to public and private telecommunications networks and user data privacy.

ETSI is custodian of these algorithms, as well as algorithms produced by other organizations. We are also custodians of other codes and test suites.

ETSI Security Algorithms Group of Experts (SAGE) provides standards makers with cryptographic algorithms and protocols specific to fraud prevention, unauthorized access to public and private telecommunications networks and user data privacy.

The group's output includes algorithms for audiovisual services, 3GPPTM, DECTTM, GSMTM, TETRA, GPRS and Universal Personal Telecommunications (UPT). Where appropriate, the group collaborates with other ETSI committees and with other organizations in order to ensure that the algorithms produced fully meet the needs of the technologies and services in which they are used.

Mobile communications

For example, working with the 3GPP Organizational Partners, SAGE has produced the A5/3 encryption algorithms for GSM and EDGE (Enhanced Data rates for GSM Evolution), and the GEA3 algorithm for the General Packet Radio Service, GPRS.

SAGE is also responsible for the specification of the Milenage algorithm set, an example algorithm set for the 3GPP authentication and key generation functions.

SAGE has also developed security algorithms for the UMTS radio interface (UTRA) in collaboration with the 3GPP™ Organizational Partners.

Whilst the algorithms are considered to be extremely robust, there is always a need to have alternative solutions ready should a breach of security ever occur. For this reason, SAGE has produced an alternative set of security algorithms for UTRA and keeps working on new algorithms to anticipate future security needs.

ETSI's custodian role

Implementation of the various algorithms is generally subject to a license which restricts their utilization to the telecommunications equipment or service for which they have been designed.

ETSI acts as a custodian for the algorithms developed by SAGE, as well as other codes and algorithms, and is responsible for the distribution and licensing of confidential information and documents.

The following is a list of the 20 latest published ETSI standards on algorithms.

A full list of related standards in the public domain is accessible via the ETSI standards search. Via this interface you can also subscribe for alerts on updates of ETSI standards.

Standard No. Standard title.
TS 126 445 Universal Mobile Telecommunications System (UMTS); LTE; Codec for Enhanced Voice Services (EVS); Detailed algorithmic description (3GPP TS 26.445 version 15.0.0 Release 15)
TS 155 253 Digital cellular telecommunications system (Phase 2+) (GSM); Specification of the GEA5 encryption and GIA5 integrity algorithms for General Packet Radio Service (GPRS); Design conformance test data (3GPP TS 55.253 version 15.0.0 Release 15)
TS 155 236 Digital cellular telecommunications system (Phase 2+) (GSM); Specification of A8_V MILENAGE Algorithm: An example algorithm for the key generation function A8_V (3GPP TS 55.236 version 15.0.0 Release 15)
TS 155 241 Digital cellular telecommunications system (Phase 2+) (GSM); Specification of the GIA4 integrity algorithm for General Packet Radio Service (GPRS); GIA4 specification (3GPP TS 55.241 version 13.0.1 Release 13)
TR 155 919 Digital cellular telecommunications system (Phase 2+) (GSM); 3G Security; Specification of the A5/3 encryption algorithms for GSM and ECSD, and the GEA3 encryption algorithm for GPRS; Document 4: Design and evaluation report (3GPP TR 55.919 version 15.0.0 Release 15)
TS 155 217 Digital cellular telecommunications system (Phase 2+) (GSM); 3G Security; Specification of the A5/3 encryption algorithms for GSM and ECSD, and the GEA3 encryption algorithm for GPRS; Document 2: Implementors' test data (3GPP TS 55.217 version 15.0.0 Release 15)
TS 155 218 Digital cellular telecommunications system (Phase 2+) (GSM); 3G Security; Specification of the A5/3 encryption algorithms for GSM and ECSD, and the GEA3 encryption algorithm for GPRS; Document 3: Design conformance test data (3GPP TS 55.218 version 15.0.0 Release 15)
TS 155 242 Digital cellular telecommunications system (Phase 2+) (GSM); Specification of the GIA4 integrity algorithm for General Packet Radio Service (GPRS); Implementers' test data (3GPP TS 55.242 version 15.0.0 Release 15)
TS 155 251 Digital cellular telecommunications system (Phase 2+) (GSM); Specification of the GEA5 and GIA5 encryption algorithms for General Packet Radio Service (GPRS); GEA5 and GIA5 algorithm specification (3GPP TS 55.251 version 13.0.1 Release 13)
TR 135 935 Universal Mobile Telecommunications System (UMTS); LTE; Specification of the TUAK algorithm set: A second example algorithm set for the 3GPP authentication and key generation functions f1, f1*, f2, f3, f4, f5 and f5*; Document 5: Performance evaluation (3GPP TR 35.935 version 15.0.0 Release 15)
TS 155 241 Digital cellular telecommunications system (Phase 2+) (GSM); Specification of the GIA4 integrity algorithm for General Packet Radio Service (GPRS); GIA4 specification (3GPP TS 55.241 version 15.0.1 Release 15)
TR 135 936 Universal Mobile Telecommunications System (UMTS); LTE; Specification of the TUAK algorithm set: A second example algorithm set for the 3GPP authentication and key generation functions f1, f1*, f2 ,f3, f4, f5 and f5*; Document 6: Security assessment (3GPP TR 35.936 version 15.0.0 Release 15)
TS 155 216 Digital cellular telecommunications system (Phase 2+) (GSM); 3G Security; Specification of the A5/3 encryption algorithms for GSM and ECSD, and the GEA3 encryption algorithm for GPRS; Document 1: A5/3 and GEA3 specifications (3GPP TS 55.216 version 15.0.0 Release 15)
TS 155 243 Digital cellular telecommunications system (Phase 2+) (GSM); Specification of the GIA4 integrity algorithm for General Packet Radio Service (GPRS); Design conformance test data (3GPP TS 55.243 version 15.0.0 Release 15)
TS 155 251 Digital cellular telecommunications system (Phase 2+) (GSM); Specification of the GEA5 and GIA5 encryption algorithms for General Packet Radio Service (GPRS); GEA5 and GIA5 algorithm specification (3GPP TS 55.251 version 15.0.0 Release 15)
TS 155 251 Digital cellular telecommunications system (Phase 2+) (GSM); Specification of the GEA5 and GIA5 encryption algorithms for General Packet Radio Service (GPRS); GEA5 and GIA5 algorithm specification (3GPP TS 55.251 version 14.0.1 Release 14)
TS 155 241 Digital cellular telecommunications system (Phase 2+) (GSM); Specification of the GIA4 integrity algorithm for General Packet Radio Service (GPRS); GIA4 specification (3GPP TS 55.241 version 14.0.1 Release 14)
TS 155 252 Digital cellular telecommunications system (Phase 2+) (GSM); Specification of the GEA5 encryption and GIA5 integrity algorithms for General Packet Radio Service (GPRS); Implementers' test data (3GPP TS 55.252 version 15.0.0 Release 15)
TR 135 934 Universal Mobile Telecommunications System (UMTS); LTE; Specification of the TUAK algorithm set: A second example algorithm set for the 3GPP authentication and key generation functions f1, f1*, f2, f3, f4, f5 and f5*; Document 4: Report on the design and evaluation (3GPP TR 35.934 version 14.0.1 Release 14)
TR 135 934 Universal Mobile Telecommunications System (UMTS); LTE; Specification of the TUAK algorithm set: A second example algorithm set for the 3GPP authentication and key generation functions f1, f1*, f2, f3, f4, f5 and f5*; Document 4: Report on the design and evaluation (3GPP TR 35.934 version 15.0.1 Release 15)