The purpose of ETSI TS 101 053-4 is to specify the rules for the management of the TETRA standard authentication and key management algorithm set TAA1. This algorithm set is intended for air interface security in TETRA products.

The specification for TAA1 consists of the following three parts:

• Part 1: Algorithm specification;
• Part 2: Design conformance test data;
• Part 3: Algorithm input/output test data.

The procedures described in the present document apply to Parts 1 and 2 of the specifications. Parts 1 and 2 are confidential for each of the algorithms.

Part 3 of each of the specifications is not confidential and can be obtained directly from the TAA1 Custodian (see clause 5.2). There are no restrictions on the distribution of this part of the specifications.

The management structure is defined in clause 4. This structure is defined in terms of the principals involved in the management of TAA1 (ETSI, ETSI Technical Committee TCCE, TAA1 Custodian and approved recipients) together with the relationships and interactions between them.

The procedures for delivering TAA1 to approved recipients are defined in clause 5. This clause is supplemented by annex A which specifies the items which are to be delivered.

Clause 6 is concerned with the criteria for approving an organization for receipt of TAA1 and with the responsibilities of an approved recipient. This clause is supplemented by annex B which contains a Confidentiality and Restricted Usage Undertaking to be signed by each approved recipient.

Clause 7 is concerned with the appointment and responsibilities of the TAA1 Custodian.