Sigma Unit
The Sigma Unit (S-unit) is the highest security area within Black Mountain. It is used for handling reality critical assets, including the Null Driver authentication keys, and houses the offices of the Adjudication and Internal Security departments. It also contains accommodation for the members of staff who permanently work there, known as residents. The entire Unit is surrounded by Dynamic Containment Array (DCA) force fields. An interdiction matrix system and automated turrets provide further security to the perimeter. The cost of its security systems makes it one of the most expensive spaces on the planet. It is gated by a Sentry Antechamber.
A Sigma security clearance at minimum is required for access to the area, with some areas requiring Sigma Star. Only those with a "need for presence" are permitted to be there, even if they possess the required clearance; personnel who have completed their tasks in the Unit are required to leave immediately. Personnel requiring access must submit a form which may be approved or denied without reason. The security of the Sigma Unit is maintained exclusively by Internal Security agents, and Raven Facility Protection Division officers are not permitted inside its perimeter unless appropriately cleared and granted access via the request process.
Areas
The main areas of the Sigma Unit include the Adjudication offices, the Internal Security offices, and an accommodation section shared by all resident staff. The Technical Systems wing includes its own Cryptographics section, where the root authority for all of Raven's cryptographic key material is stored. A small area dedicated to Black Research holds Vault Control and the Master Key Vault, which holds the authentication keys for the Null Driver.
The Sigma Unit is like a miniature Black Mountain, and replicates much of the infrastructure of The Descent in a vastly scaled down model with highly cleared staff members. It contains its own Technical Systems and Logistics divisions, in order to maintain the unit's power, life support, and computer systems, as well as vetting deliveries of consumables into the unit. All material leaving the unit is required to be degaussed, irradiated, burned to ash, and subjected to entropic radiation to ensure no remnants of information, even on the atomic level, remain.
Security
Vault Control
Vault Control is the security checkpoint zone that gates access to the Master Key Vault. It is patrolled 24/7 and sealed behind multiple blast doors. It is also where the vault sensors are monitored, including the status of the internal systems such as temperature and atmospherics.
Master Key Vault
The Master Key Vault holds the Metatron Hardline cryptographic modules that hold the keys that gate access to the Black Terminal, and in turn, the Null Driver. It also holds the Key Vault Security Controller (KVSC) that authenticates council decisions. The KVSC, by agreement of a council majority, is able to unlock the Null Driver keys for use. It also signs all council verdicts.
Verdict Deliberation Room
This is where adjudicators are able to come together and deliberate on verdicts. It is equipped with a state-of-the-art verification system linked to the Key Vault Security Controller (KVSC) that verifies member license cards, bioprints, and mental activity patterns. The room is encapsulated in its own forcefield to ensure absolute confidentiality.
Adjudication Chambers
This is the place where council meetings are held. It consists of a large table around which members sit and is located minutes away from the Deliberation Room.