Military Communications and Information Technology: A Trusted ...

Chapter 4: Information Assurance & Cyber Defence
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of the secure transport layer services can also provide additional protection for
availability of the HAAG by introducing additional controls for allowed connections
and resource consumption.
3) Cryptographic Services
The main Cryptographic Services required by the HAAG are related to integrity
protection and authentication. The public key encryption module provides
functionality required to verify digital signatures of the XML security labels. This
functionality includes implementation of appropriate public-key cryptographic
algorithms, hash functions, and certificate validation mechanisms. It can be also
used in order to provide PKI-based authentication of the HAAG users.
Additional Cryptographic Services might be required for authentication
of the users and securing the communication channel between the HAAG and
the user (if applicable). These additional cryptographic services include message authentication
codes (e.g. keyed hash function) and symmetric encryption algorithms.
4) Cyber defence component
In order to provide an adequate security and assurance level for information
exchange between security domains, the HAAG relies on preventive and reactive
services provided by the NATO cyber defence infrastructure. The NATO Cyber
Defence Services of particular relevance to the HAAG include monitoring, data
fusion, dynamic risk assessment and alert generation.
The feedback from the Cyber Defence Services can be used to influence and
reconfigure the security policies enforced by the HAAG. The possibility of dynamic
update of system security policy based on the identified threat level has been
studied in [18]. In [19] an approach for integration of alerts, generated based on
information received from various cyber sensors, with contextual security policies
has been investigated. The alerts, received in the Intrusion Detection Message
Exchange Format (IDMEF) [20], are mapped to contexts and response strategies
involving changes to the enforced security policy.
5) CIPE Content Filters
The CIPE Content Filters are separate modules of the CIPE architecture, which
can be provided by the third party. As opposed to the CIPE Framework, which
is part of the HAAG TOE, the Content Filters are therefore treated as external
services provided by the HAAG Operating Environment.
The CIPE Service provides for separation of the CIPEF from the Content
Filters. The Content Filters, the only CIPE Service component that directly handles
the contents of a data object, must be separated and managed outside of the other
components of the CIPE Service due to the potential threats and vulnerabilities
that may be exposed by the handling of data objects. The CIPEF communicates
with the Content Filters via the Content Filter Interface.