RedBlack Separation

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Red/Black Separation

• Introduction and Electronic Warfare Application

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Overview

• Topicality
• Definition of Terms
• Aircraft MIL-STD-232A
• Physical Protection
• Electronic Warfare Application
• Electro-Magnetic Barrier
• Grounding, Bonding and Shielding
• Physical Separation
• Filtering and Isolation

Separation
Red
Black
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Topicality

• Red/Black Separation is a concept that was
  created to differentiate between TEMPEST level
  requirements and the protection of Secret or even
  Top Secret information within a facility.
• It has been expanded to include systems
• Becoming widely used as an installation design
  criteria for aircraft as more commercial hardware
  is being used for military applications,
  especially avionics.

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Definitions of Terms
Red / Black Separation

• Red/Black Separation denotes the separation of
  systems that handle national security information
  (RED), in electrical form, from those that handle
  non-national security information (BLACK) in the
  same form.
• Electrical and Electronic
• Circuits
• Components
• Equipment
• Systems
• Areas where they are contained
• Physical Protection

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Physical Protection

• This briefing addresses the design of a proper EM
  barrier and not the requirements for physical
  protection.
• It is assumed that any red equipment used in the
  EW suite will be considered unclassified after a
  normal shutdown.
• The CONOPS of the aircraft is assumed to provide
  sufficient physical protection to be considered a
  Limited Exclusion Area (LEA) when the equipment
  is powered.

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Definitions of Terms
Red National Security Info Area

• Red The area designated for the installation of
  equipment processing national security
  information (classified information or
  unencrypted classified information)
• Black The area designated for the installation
  of equipment processing unclassified information
  or encrypted information

Black Unclassified or Encrypted Area
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Definitions of Terms

Red

• Signals denote transmitted data to/from equipment
  contained in a Red area and from a Red area to a
  Black area
• Types
• Analog
• Digital
• Power transmissions
• AC
• DC

Black
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Definitions of Terms
Facility/LEA
Red / Black Separation
Red Classified Area With Sensitive Data

• Facility denotes the structure that encompasses
  both red and black equipment also known as
  Limited Exclusion Area (LEA).
• Equipment includes only external metallic case of
  a LRU that processes the type of data in question
  and not the wiring extending outside of the LRU

Black Unclassified or Encrypted Area
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Definitions of Terms
Facility/LEA
Red / Black Separation
Red Classified Area With Sensitive Data

• Entrance Plate denotes the barrier through which
  all conductors pass into the facility
• EM barrier
• Equipment case
• Metallic power distribution facilities
• Signal cable shields

Black Unclassified or Encrypted Area
Entrance Plate/EM Barrier
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Definitions of Terms
Earth Electrode Subsystem (EESS)
Facility/LEA
Red / Black Separation
Red Classified Area With Sensitive Data

• Earth Electrode Subsystem (EESS) is typically a
  ring ground around the facility, augmented by an
  array varying length rods to ground that are
  driven near the facility entrance plate to
  provide a low impedance path to earth.
• Red Equipment Area (REA) denotes the area
  encompassing the red equipment

Black Unclassified or Encrypted Area
Entrance Plate/EM Barrier
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Aircraft as the EESS
Aircraft
LEA Perimeter
Red / Black Separation
Red Classified Area With Sensitive Data

• The aircraft framing and skin can be
• considered to be the ground (Earth)
• potential.
• Proper bonding and grounding
• techniques shall act as the ring
• ground to the aircraft.
• A LEA perimeter must be
• established within the EESS.
• Red/Black separation is the proper
• design of the perimeter barrier and
• the internal barriers for the
• Red equipment and the Black equipment

Black Unclassified or Encrypted Area
Entrance Plate/EM Barrier
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Electronic Warfare Application

• Case Study

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Typical Integrated EW System
EW Integration Processor Terma AN/ALQ-213
Avionics
Missile Warning Directed IR Countermeasures
RF Jammer
RWR
Dispenser
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Applying the Electro-Magnetic Barrier

• Grounding, Bonding and Shielding
• Physical Separation
• Filtering and Isolation

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Grounding Bonding and Shielding (GBS)

• According to MIL-HDBK-232A, Control of
  compromising
• emanations, EMP/HEMP protection, and RED/BLACK
  isolation
• depends fundamentally on proper GBS design.
• Grounding denotes the electrically interconnected
  systems of conductors and conductive elements
  that provide current paths to earth.
• Bonding denotes the process of connecting
  together metal parts so that they make low
  resistance electrical contact for direct current
  and lower frequency alternating currents.
• The process of making a satisfactory electrical
  connection between the structure, including the
  metal skin, of an object or vehicle, and the mass
  of the Earth, to ensure a common potential with
  the Earth
• Shielding denotes a housing, screen, or cover
  which substantially reduces the coupling of
  electric and electro-magnetic fields into or out
  of circuits

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Grounding Bonding Requirements

• Multiple ground conductors to be installed from
  the signal cable shields to the aircraft along
  the wiring path
• Ground conductors shall be less than 3.6m to
  protect against the vulnerability of EMP/HEMP or
  lightning
• Ground conductors shall only be soldered if there
  is low risk from power surges which may cause the
  solder to melt.
• Shield grounds not to be spliced
• All power source filters shall have their case
  bonded to the LRU enclosure as that is considered
  the REA entrance plate

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GB Design Considerations
EW Integration Processor Terma AN/ALQ-213
Avionics
lt3.6m
Missile Warning Directed IR Countermeasures
RF Jammer
RWR
Dispenser
18
Shielding Requirements

• All signal cables for Red and Black data shall
  have an overall nonferrous circumferential
  shield.
• Circumferential Cable Shields
• meet the conductance requirements of the standard
  ground leads with proper bonding
• Encompass the cable at both ends
• Bonding the shield circumference to the equipment
  enclosure
• Use a connector which has a conductive shell
• 360-degree contact with both the shield and with
  the mating connector
• Mandates a group-A requirement for the wiring of
  the complete EW suite including the cables to the
  avionics.
• Twisted pair wire bundles shall have at least an
  overall shield
• An additional 3dB of attenuation gained by
  shielding of each pair (Twisted Shielded Pair
  (TSP)

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Shielding Design Considerations
EW Integration Processor Terma AN/ALQ-213
Avionics
lt3.6m
Missile Warning Directed IR Countermeasures
RF Jammer
RWR
Dispenser
20
Signal Distribution Guidance

• In addition to the grounding and shielding
  requirements, analog and digital signal conductor
  selection and design shall have a goal of
  keeping
• Voltage levels low
• All pairs properly terminated
• Impedance of connections properly matched
• Shields properly closed and grounded

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Physical Separation

• The goal of system design for Red equipment
  installation is to create physical, electrical
  and EM barriers around the equipment
• To meet this requirement, an REA must be
  established within an LEA.
• The aircraft itself acts as the facility, EESS
  and the LEA. MIL-HDBK-232A sections 5.3.1 and
  5.3.2 deal specifically with this case.

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Physical Separation Requirements

• Equipment
• Red and Black equipment shall be separated by at
  least 0.9m.
• Red equipment shall be separated from COMSEC
  equipment by at least 0.9m.
• Black equipment shall be separated from COMSEC by
  1.8m.
• Red equipment shall be separated by at least 50mm
  within the aircraft.
• Black voice equipment shall be separated from Red
  equipment by at least 1.8m.
• If visual inspection of the wiring for tampering
  is a requirement, then all equipment within the
  aircraft shall be at least 0.9m from the walls.
• Patch Panels
• Red Patch panels with Red signals that are
  filtered or isolated shall be separated from
  Black signal patch panels by at least 50mm.
• Red Patch panels with Red signals that are not
  filtered or isolated shall be separated from
  Black signal patch panels by at least 0.9m.

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Physical SeparationEquipment
All distance in meters
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Physical Separation RequirementsWiring

• Filtered (or isolated) Red and Black signal wires
  and power wires shall be separated by at least
  50mm.
• In the case that filtered (or isolated) Red and
  Black wire runs are parallel and exceed 30m, the
  separation of the wires shall be 150mm.
• Non-filtered (or non-isolated) Red and Black
  signal wires and power wires shall be separated
  by at least 0.9m.

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Separation Design Considerations
gt0.9m
EW Integration Processor Terma AN/ALQ-213
gt0.9m
Avionics
lt3.6m
Missile Warning Directed IR Countermeasures
RF Jammer
RWR
Dispenser
All Red Equipment and wiring is separated by 50mm
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Filtering and Isolation

• The filtering and isolation guidance will follow
  MIL-HDBK-232A
• and therefore will be considered to accomplish
  the same design
• goal though through different physical measures.
  
• Focused on all unencrypted signals that cross
  from
• REA to Black equipment in the LEA
• LEA out of the aircraft
• According to MIL-HDBK-232A, filtering is not
  necessary for the following data
• Encrypted data
• Data processed on TEMPEST rated equipment,
• Data processed on equipment that is properly
  separated and with proper physical protection
  methods
• Filtering denotes various electric, electronic or
  optical devices used to reject signals or
  radiations of certain frequencies while allowing
  others to pass

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Filtering and Isolation Application Assumptions

• EW Integrated Controller
• Will not drive requirements for physical security
  outside of ML/V actions
• Will not be TEMPEST certified
• All loading operations of sensitive data will be
  encrypted
• EW Suite will be cleared during a normal
  shutdown

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Shared Power Filtering Requirement

• According to MIL-STD-232A, separate power sources
  should exist for Red equipment and Black
  equipment.
• This requirement is mitigated in the handbook in
  cases of small facility size but the additional
  requirement of filtering is necessary for the Red
  equipment
• For this example, shared power is assumed

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Power Filtering Requirements

• Power filtering requirements refer to two
  separate baselines within the MIL-HDBK-232A
• In section 5.2.6, the requirement is reference to
  MIL-F-15733 which states the following
  attenuation
• 50 dB at 150 kHz
• 60 dB at 300 kHz through 1 GHz
• Section 5.5.1.5 details a more stringent set of
  requirements for passive filters
• At least 100 dB from 14 kHz to 1 GHz
• Active filters may be used to meet these
  requirements due to the space limitations of the
  group-A installation

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Power Filtering Design Considerations
gt0.9m
EW Integration Processor Terma AN/ALQ-213
gt0.9m
Avionics
lt3.6m
Missile Warning Directed IR Countermeasures
RF Jammer
RWR
Dispenser
All Red Equipment and wiring is separated by 50mm
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Red Equipment/Black Signal Filtering Requirements

• The goal of the design should be to avoid the use
  of an overall shielded cable containing both Red
  and Black lines.
• Filtering or isolation allows lines from Red
  processors that carry Black data contained in an
  overall shielded cable to be connected to Black
  equipment.
• Red equipment transmission of Black data to Black
  equipment can be divided into multiple sets of
  requirements
• communication data that could be connected to a
  radio headset or headset
• low-speed unencrypted data
• high-speed unencrypted data

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Voice/Radio Connections

• All signals from Red equipment that are to be
  connected to the radio headset need to be
  filtered
• Audio from the EW Integrated Controller will be
• transmitted to the intercom system and
• to the aircrew headsets,
• all wires should be shielded and filtered.
• Since 100 dB at 14kHz is the worst case
  requirement,
• the audio should be filtered at this
  specification.
• Active filtering will provide the best filter
  characteristics
• for maintaining as much of the audio as possible
• In addition, the audio signal wires shall be
  contained
• in a dedicated metallic conduit to the radio
  rack

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Voice Filtering Design Considerations
gt0.9m
EW Integration Processor Terma AN/ALQ-213
gt0.9m
Avionics
lt3.6m
Missile Warning Directed IR Countermeasures
RF Jammer
RWR
Dispenser
All Red Equipment and wiring is separated by 50mm
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Black Data Signals from Red Equipment

• Low-Speed Signals
• Low-speed signals (up to 2.4 kbs) may use simple
  relays to meet the isolation requirements of
  passing Black information from Red equipment to
  Black equipment.
• High-Speed Signals
• High-speed signals require optical isolators.
• These isolators are divided into two categories
• fibre-optic cables
• space separated source/detector.
• Optical isolators can be used but fibre-optic
  cables are the preferred method of isolating
  signals.

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Data Filtering Design Considerations
Avionics
gt0.9m
EW Integration Processor Terma AN/ALQ-213
gt0.9m
Fiber Optic Connection
lt3.6m
Missile Warning Directed IR Countermeasures
RF Jammer
RWR
Dispenser
All Red Equipment and wiring is separated by 50mm
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Red Equipment Signals to Red Equipment

• The signal wires to from Red Equipment to other
  Red Equipment shall be enclosed in a non-ferrous
  circumferential shield.

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Completed Example
Avionics
gt0.9m
EW Integration Processor Terma AN/ALQ-213
gt0.9m
Fiber Optic Connection
lt3.6m
Missile Warning Directed IR Countermeasures
RF Jammer
RWR
Dispenser
All Red Equipment and wiring is separated by 50mm
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Questions?