Communications for Isolated Personnel
*Personal Survival Kits*. Creating and carrying a personal survival kit will augment any issued survival equipment in order to help an isolated person survive. Individuals must personalize their survival kits for the operating environment. Consider including the following items in a personal survival kit: water, shade tarp, [firearms and] ammunition, radio, personal locator beacon (PLB), satellite phone, commercial tracking device, maps, compass, and emergency signaling devices, local purchase cell phone, sun block, insect repellent, head net, space blanket, burlap, poncho, a mirror, infrared (IR) and visible lights (e.g.: Fire Flies, laser pointer, Micro Lights, Phoenix, chemical lights, etc.), 3’x3’ bright colored cloth, 1 sq. inch of glint tape, knife or multi-tool, fire starter, candle, button compass, water purification tablets, three 1-gallon zip lock bags, large plastic leaf/trash bag (for water storage and protection from the elements), 100 ft. parachute cord, gloves, large needles, dental floss, safety pins, first aid items, and any needed medications. If extra clothing is included, it should be lightweight, windproof, waterproof, and appropriate for cultural, environmental, and seasonal conditions. An outer jacket and hat and sturdy local footwear could be useful for blending with the local population. Having a small or moderate amount of local and U.S. currency may be useful for purchasing supplies or materials. During pre-mission planning, personnel should consider the different survival situations when deciding what to pack in their personal survival kits. Personnel should also determine which items are necessary to retain in an emergency and which are expendable.
*Communication Plans*. The number one priority for an isolated person is to contact friendly authorities to report their identity and location by using the established communications plan. Document the communication plan on the EPA. Communication plans should address both short-term and long-term communication with friendly forces. The plan should include radio, phone (cell or satellite) information, contact times, frequencies, and intentions.
*Signaling for Recovery*. Timely and effective signaling will greatly help efforts to report, locate, identify, support, and recover isolated personnel. The best location information comes from the individual who is equipped with a survival radio, cell phone, or other communication device and trained to report their current position. The isolated person’s participation in providing their location to recovery forces is by far the most accurate, efficient, and expedient means of locating their position for recovery. Another good source for determining location is if recovery forces locate a radio’s signal or detect a visual signal. Recovery forces will look at the isolated person’s EPA to determine their signaling intentions. Based on the information in the EPA, recovery forces can search areas and potentially authenticate the identity of the isolated person.
*Technical Communication*. Personnel should document their EPA with detailed information on available communication device(s) to include make, model, frequency, serial number, SIM card data, international mobile equipment identity (IMEI) or electronic serial numbers (ESNs). Personnel should attempt to contact friendly authorities by transmitting a distress call via any available communication device. Isolated personnel should be prepared to identify themselves, authenticate, and transmit their location when directed. Besides requiring batteries, there are other potential issues when relying on radios or cell phones. Radios or cell phones may malfunction, sustain damage, become lost/stolen, or lose their programming/power. Cell phones have an additional connectivity concern in that they may be unable to obtain a cell tower’s signal or are incompatible with a country’s communication system. Personnel should anticipate these problems and prepare to overcome them.
*Personal Locator Beacons (PLBs)*. PLBs are a family of hand-held devices that transmit distress signals on an internationally monitored frequency. PLBs are not the primary means for alerting recovery forces during an isolating event. Personnel should follow the communications plan, as annotated in their EPA, to determine the appropriate time to activate a PLB. If necessary, personnel should use PLBs to report their situation when other prescribed methods are not available or are not working. Personnel should only use a PLB when all other means of reporting are unavailable, exhausted, or ineffective. They only broadcast distress and homing signals. Personnel should annotate their PLB’s unique identifier number in their EPA or other similar emergency action plan. This will greatly assist alerted recovery personnel in confirming whether a transmission is an actual report of an isolation event or an inadvertent alarm. When employing a PLB, the greatest probability of successful satellite reception occurs when a PLB has a clear view of the sky from horizon-to-horizon. They are capable of operating in an environment with less than a complete view of both horizons (e.g., a valley, canyon, on a mountainside, wooded area, near a chain link fence, nearby or inside buildings), but any such obstruction will reduce satellite reception capability and/or degrade the PLB’s signal; however, even if reception is clear, some signal information may be delayed and take up to an hour and a half before it gets to the to the appropriate agency which can respond to an activation.
*Visual Signals*. Isolated personnel may find themselves in a nontechnical communication situation due to drained batteries, loss, damage, or confiscation of their radio. PR plans should include alternate procedures for signaling when radio contact fails, is not feasible, or is not available.
Strobes can be used at night to identify positions. If prior coordination has been conducted with supporting aviation units, strobes may be used to signal pilots. To reduce detection when used, strobe lights should be placed in holes so they can only be viewed from above. Strobes with infrared covers can be used if there has been prior coordination with the aircrew.
*Ground-to-Air Signals (GTAS)*. A GTAS is a supplemental system to radio or cell phone communications. They are non-directional signals that identify an individual’s general location. Signal construction could consist of colored (parachute) panels, specially aligned radar reflective devices, glint tape, specially shaped IR reflectors, metallic trash (cans, foil, sheet metal, screen wire, vehicle parts), building debris, natural materials (e.g., sticks, logs, rocks, sod, dug or turned soil, vegetation), to make a visually recognizable or meaningful signal. Individuals should annotate the EPA with the type of signal they intend to use and the distance and direction they intend to travel in relation to all visual signals. Personnel should choose materials appropriate to the environment and those that will not degrade in weather. Isolated personnel may signal the approaching recovery asset by using a directional signal aimed towards the recovery asset to pinpoint the individual’s specific location. Directional signals include mirrors, flashlights, laser lights, shielded IR lights, chem-lights and specially shaped IR reflectors. If isolated in a hostile environment, and in voice contact with a recovery force, personnel should employ non-directional signals, such as flares and smoke, only when directed. Isolated personnel may need to improvise signaling devices (car or bike mirror, polished metal, bright colored cloth, etc.) and become very creative to avoid enemy detection.
*Recovery*. Availability of potential U.S., allied or regional recovery assets are dependent on the situation at the time of isolation; time, threats, and distance are limiting factors. Because of the long distances and lack of traditional recovery assets, it may take a significant amount of time to execute a recovery mission. Personnel should plan to survive and evade unassisted for a minimum of 72-96 hours. However, recovery may take longer. Isolated personnel must also be prepared for long-term unassisted evasion.
A DRYAD cipher sheet contains 25 lines or rows of scrambled letters. Each line is labeled by the letters A to Y in a column on the left of the page. Each row contains a random permutation of the letters A through Y. The letters in each row are grouped into 10 columns labeled 0 through 9. The columns under 0, 1, 2 and 5 have more letters than the other digits, which have just two each.
While crude, the DRYAD Numeral Cipher / Authentication System has the advantage of being fast, relatively easy and requires no extra equipment. The presence of more cipher-text columns under the digits 0, 1, 2 and 5, is intended to make ciphertext frequency analysis more difficult. But much of the security comes from keeping the cryptoperiod short.
DRYAD can be used in two modes, authentication or encryption.
DRYAD Authentication - For authentication, a challenging station selects a letter at random from the left most column followed by a second (randomly selected) letter in the row of the first chosen letter. The station being challenged would then authenticate by picking the letter directly below the row and position of the second letter selected.
DRYAD Encryption - The second mode is used to encrypt short numeric information (such as map coordinates or a new radio frequency). The coder arbitrarily selects two letters at random. The first letter designates a row in the current active page. The second one is used similarly to the authentication mode, except that the letter immediately to the right is selected. This selected letter is called the "SET LETTER."
Numbers are enciphered one digit at a time. A ciphertext letter is chosen from the selected row (the row designated by the SET LETTER) in the column under the plain text digit. If the digit occurs more than once in the number, the coder is instructed to choose a different letter in the same column. All the digits in a single plaintext number are encoded from the same row.
DRYAD tables can be created by generating randomly ordered alphabets and then formatting the tables as shown above. Websites such as random.org claim to provide truly random data. The pseudo-random generator and spreadsheet formatting in MS Excel allows for rapid generation of DRYAD tables. Operators will have to weigh the advantages of rapid generation and formatting of DRYAD tables against the security of the pseudo-random generator (the Mersenne Twister algorithm) used in programs like MS Excel.
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