Military Communications and Information Technology: A Trusted ...

384 Military Communications and Information Technology...
Figure 5. HAAG as a separation service
The HAAG service is responsible for enforcing access control based on advanced
security policies, taking into account the properties of users (e.g. clearance
level and his role in the organization), properties of devices (e.g. hardware cryptographic
modules, trusted computing platform), and properties of the information
(e.g. its validity time, sensitivity and area of application).
In this phase, the traditional characterization of information through simple
metadata (or so-called security label e.g. NATO Secret releasable to Australia),
is replaced by a more detailed (and complex) metadata describing the information
(e.g. logistic data relevant to transport of goods to Australian troops based
in Afghanistan). Similarly, instead of being characterized only by a clearance level,
the end-user would be characterized by metadata describing his role, affiliation, and
trustworthiness. The terminal would also have to be characterized by additional
metadata describing its trustworthiness, such as none, basic, normal, enhanced and
high, instead of being just characterized by the network domain in which it is located.
The required separation of information flows in Phase 2 can only be achieved
by using advanced cryptography, including encryption of both data at rest and data
in transfer. Recently, several relevant new cryptographic techniques have been
developed, including homomorphic encryption enabling processing of encrypted
data [12] and wild-carded identity-based encryption [13], potentially enabling
encryption of data for groups of user, e.g., users playing the same role within organization,
and effective key management.
V. High level design
One of the current activities coordinated by the NCIA is development of high
level design (HLD) for the HAAG. The target of the HLD is Phase 1 and Phase 2
of the HAAG as described in the previous section.