Guralp Systems CMG-DCM build <10,000 - Manual (Page 19)

Acquisition Modules and Platinum Firmware Equipment Overview
Platinum firmware has support for CD1.1 frame generation and forwarding
with strong authentication provided by an optional embedded Spyrus
hardware encryption device, allowing CMG-EAMs and CMG-NAMs to form
the basis of a secure CD1.1 network.
Data transmitted in CD1.1 format use strong authentication and digital
signatures to ensure that the received data are exactly those transmitted: i.e.
that they have not been tampered with during transmission.
Platinum firmware contains many facilities to support CD1.1. These are
documented in a separate manual, MAN-EAM-1100, which is available on
request from [email protected].
MAN-EAM-0003 19 Issue E - February 2014