I.B. + M.A. DE LANDE LONG
SOFTWARE + CONSULTANCY

Overview of ESA Authentication Unit (AU)

Telecommand Authentication can improve mission security by protecting a spacecraft against unauthorised commands sent by a hostile party. Our product range includes support for the ESA Telecommand Authentication Unit (AU), which is an ESA extension to the standard CCSDS Packet Telecommand Architecture.

Add Authentication tail

An extra field, the authentication tail, is added to the end of each telecommand data block. The authentication tail contains a counter and a "signature" to guarantee that the command is genuine. The signature is a complex function of a secret key, the counter and the telecommand data.

The telecommand data itself is not encrypted.

The details of the signature, keys and counters are described in the AU features.

Remove Authentication tail

The Authentication Unit Shell package is a software component which implements all the features of the ground and space ends of the ESA AU. The Telecommand Encoder Shell and Telecommand Decoder Shell packages provide optional support for the ESA AU.

As an alternative to the ESA AU, our product range includes the Segment Level Security Interface (SLSI), which is an interface for external implementation of security features such as authentication.

AU Features AU Shell TC Encoder Shell TC Decoder Shell