This specification takes notice of the Security Principles and Objectives as set out in [1]. It contains an evaluation of perceived threats to 3GPP and produces subsequently a list of security requirements to address these threats. As teleservices and applications will not, in general, be standardised, it is difficult to predict their exact nature. Therefore, this specification considers all security threats and aims at listing generic security requirements that shall be applicable irrespective of the actual services offered. The list of threats and requirements may however need to be updated as the 3GPP system evolves. The threat analysis performed relies to a large extent on previous experiences with 2G systems, in particular GSM, and takes into account known problems from that area. The security requirements listed in this specification shall be used as input for the choice of security features and the design of the 3GPP security architecture as specified in [2]. The structure of this technical specification is as follows:

• clause 2 lists the references used in this specification;
• clause 3 lists the definitions and abbreviations used in this specification;
• clause 4 contains a reference to the general objectives for 3G security;
• clause 5 contains an overview of the context in which the security architecture of 3G is designed;
• clause 6 contains a list of identified security threats to 3G, and gives some results from the threat analyses that have been performed;
• clause 7 contains an overview of the risk assessment resulting from the threat analyses performed
• clause 8 contains the resulting list of security requirements for 3G and indicates how these requirements relate to the threats and the security objectives .

Finally, Annex A gives some more detailed information on threats and risks connected to so called false base station attacks.

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

• References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.

The general objectives for 3G security features have been stated as [1]:

1. to ensure that information generated by or relating to a user is adequately protected against misuse or misappropriation;
2. to ensure that the resources and services provided by serving networks and home environments are adequately protected against misuse or misappropriation;
3. to ensure that the security features standardised are compatible with world-wide availability (There shall be at least one ciphering algorithm that can be exported on a world-wide basis (in accordance with the Wassenaar agreement));
4. to ensure that the security features are adequately standardised to ensure world-wide interoperability and roaming between different serving networks;
5. to ensure that the level of protection afforded to users and providers of services is better than that provided in contemporary fixed and mobile networks;
6. to ensure that the implementation of 3G security features and mechanisms can be extended and enhanced as required by new threats and services.

Furthermore it has been agreed that the basic security features employed in 2G systems will be retained, or where needed enhanced. These include:

• subscriber authentication,
• radio interface encryption,
• subscriber identity confidentiality,
• use of removable subscriber module,
• secure application layer channel between subscriber module and home network,
• transparency of security features,
• minimised need for trust between HE and SN.

In some instances, 3G will need to be equipped with stronger or more flexible security mechanisms than those which were designed for GSM, due to new or increased threats. These will be treated in the threat analysis. Mechanisms to combating fraud in roaming situations should be included in the 3G specifications from the start. Mechanisms for lawful interception under authorisation should be included in 3G specifications from the start.