Search and Rescue Numerical Encryption Grid (SARNEG)

The Search and Rescue Numerical Encryption Grid or SARNEG is a means of encrypting map grid coordinates, and other numerical portions of a message, when that message must be sent over non-secure means. Usually this means that an isolated person is communicating his or her location to a rescue team over an unencrypted radio, but the SARNEG can be used to encrypt numbers in other types of communications as well.

To use SARNEG you first agree upon a ten-letter word with no repeating letters. A couple of examples of such words include: AFTERSHOCK and BLACKHORSE. You could also choose to use a combination of two words, such as COMBATHELP.  The word or words are simply a mnemonic to aid in remembering a sequence of ten letters.

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A F T E R S H O C K

 
To use SARNEG write the numbers 0-9, and directly below those numbers write your key word. Substitute the letters of the key word for the numbers in the grid coordinates of your location.  For example, if you are located at 56°29'54.8"N  84°59'21.9"E (Decimal 56.498552, 84.989404) in Tomsk, Russia you could send your location as SARNEG: SHRKCSST  CRKCKRAR (although why you would need search and rescue in the City of Tomsk remains a question). Using the military grid reference system, your coordinates would be: 45V UC 76232 63380, and you would send SARNEG: OHTET HEECA.  With the military grid reference system, the grid zone designator and 100,000-meter square identifier (i.e. 45V UC) are not normally transmitted as part of the SARNEG. If for some reason you did include the grid zone designator and 100,000-meter square identifier, you simply include it as part of your plaintext before the SARNEG (i.e. 45V UC, SARNEG: OHTET HEECA).

It is assumed that for search and rescue purposes you will not transmit your exact location while in a hostile area until your rescue / extraction has arrived in your general location. The SARNEG is not a high security encryption that will protect large amounts of message traffic. It is however sufficiently secure for safeguarding the numerical portions of short messages (i.e. grid coordinates), for short periods of time.

SARNEG need not only be used for search and rescue. Maybe you are operating personal radios (i.e. Amateur Band (HAM), RHA68 / PMR446 / GMRS-FRS) with family or friends and want to keep locations, dates, times, telephone numbers, and the like private, from others who might be monitoring the channel. SARNEG will let you do this.

Similar to the challenge and password, the SARNEG keyword is designated prior to each mission.