The Red Herring Cipher is an old-school pencil and paper secret writing system that was inspired by the Numbers Stations.

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As a shortwave radio listener in the 70s and 80s, I was intrigued by these mechanical sounding voices broadcasting what appeared to be these ciphers made up of these groups of numbers.  Sometimes they were in Spanish or English or other languages.  These are the so-called Numbers Stations.  I was inspired to create this RHC (redherringcipher) secret writing page for people who have interests in cryptology and/or shortwave listening (SWL). 

 

This is what I would imagine to be happening behind the scenes of a numbers station as far as the creation of the cipher itself.

 

Since the Numbers Stations fall into the clandestine type of scenario, it leaves a lot to the imagination.  This is a good thing because it is fun sometimes when you have to think outside the (drop) box.

 

(Disclaimers: This system is intended for non-commercial, hobby, entertainment and educational purposes only!  Also noted is that the name "Red Herring Cipher" [RHC] is only a title of this system and is not involved in any red herrings.  It is also it is not affiliated with Radio Habana Cuba, RHC.) 

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Using a simple pencil and a paper worksheet, you can convert each character of your Plaintext message into an encrypted 2-digit number.  These 2-digit numbers will then be separated into final 5-digit groups.  It utilizes the One-Time Pad (OTP) method of encryption.  This method has been said to be unbreakable as long as the:

 

1)  OTP Key numbers are made up of random numbers

 

2)  There are enough of them (with overage) to cover the entire message and

 

3)  It is used ONLY ONE TIME per message 

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Check Out the Documents and Get the Visuals!

 

The paperwork files below are saved as Portable Document Files (PDFs).  You need to have Acrobat Reader® to view and print these documents.  Download it free from Adobe Systems, Inc.®   (Those previous lines seems SO DATED!  I'll leave it in for legacy reasons.)

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01_Grid_Worksheet_Example.pdf

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02_Grid_Worksheet.pdf

 

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03_Legend_Page.pdf

 

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04_OTP_Batch_Page_Example.pdf

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The parts of "the system"

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The Legends Page (Conversion or Substitution Table)

The Legends Page (AKA) the Conversion Table  is used to substitute your Plaintext characters into simple two-digit numbers.  These numbers will later get encrypted at the OTP stage.  You can create a Substitution page of your own and in any way to suit your needs.

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The Grid Worksheets

This is where the work takes place.  Yourself and your intended recipients would need to print out blank Grid Worksheets (agents would most likely use graph paper).  These forms are for learning purposes.

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On this form(s) is where you set up your:

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-1  Plaintext message

-2  Legend Numbers (for the substitution)

-3  OTP-Key (then do the math)

-4  Ciphertext. 

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Symmetrically speaking, upon receiving your enciphered message, your intended recipient would reverse-order it on their form(s):

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-1  Ciphertext

-2  OTP-Key (then do the math)

-3  Legend Numbers (for the substitution)

-4  Plaintext message

 

The grid is made up of 6 columns by 9 rows (or 54) Cell Blocks for 54 five-digit groups.  In this system this is where the enciphering (via subtraction) is done on the sender's end and the deciphering (via addition) is done on the recipient's end.  Other systems may have it in reverse order (add to encipher and subtract to decipher) however it really does not matter as long as all parties are in agreement upon what to use.  Please see the Grid Worksheet Example.pdf for more info on this.

 

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The One-Time Pad (OTP) Key Numbers

 

You can print out groups of Random OTP 5-digit Key numbers to be given your intended recipients ahead of time.  These are the Key random numbers that when used with the Legend Numbers will create the Ciphertext.  Since these numbers are the Key, they would be kept secret from other parties.  In the spy, military and diplomatic worlds this would be crucial however for our purposes here it is not a biggie.  Please remember that the OTP Key Numbers are used for one message only and never used again.  Please see OTP Batch Page Example pdf.

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About "Random" numbers:

 

I have heard it said that it is very hard to get true random numbers from any computerized or mechanized system (unless it is a very sophisticated computer system).  To quote the brilliant Hungarian-American mathematician John von Neumann, (1903-1957) "Anyone who considers arithmetical methods of producing random digits is, of course, in a state of sin."  Just the fact that he was using the word "sin" means that he was really serious about that.  

A set of numbered dice, a cheap Bingo Cage or some ping pong balls with painted numbers on them will give you a much better result regarding random numbers (albeit it being a bit time-consuming). 

 

For our purposes here however, we can just take simple way and use the following Pseudo-Random Numbers Generator (PRNG) just to speed the process up and call it a day.

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Obtaining and Printing Out the "Pseudo-Random" Number Keys

 

To get a batch of OTP-Key Numbers, you can use this JavaScript Pseudo-Random Numbers Generator (PRNG) that can be found at John Walker's Fourmilab Switzerland site.

 

You can experiment with different settings for lengths and widths to fit your needs.

 

The settings here were used for the example below.

 

Output: Number of keys: 27    Line length: 0
Format: Key length: 30    Group length: 5
Composition:  Numeric
Seed:  From Clock

 

These settings were only chosen to match the worksheet and to make it easier to fill out.  You can configure them any way that you want.  On the worksheet there are 6 Cell Blocks across by 9 Cell Blocks down (totaling 54 in all).  In the key sample below there are 6 blocks across and 27 blocks down (totaling 162 blocks in all).  So there are enough blocks below to fill up 3 worksheets (6 x 27 = 162  OR  54 x 3 = 162  OR  162 / 54 = 3 which means that that is certainly enough math for today.  Here is the output:

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                  1) 55715-87927-10984-01409-63194-75774
                  2) 33097-52201-11824-33620-21700-43163
                  3) 23590-20075-74679-56484-20628-85079
                  4) 37334-95685-84634-05717-02424-53621
                  5) 00421-70799-79625-62738-69655-92187
                  6) 91086-04012-04110-77107-85121-81620
                  7) 93090-25851-40663-08527-94257-08831
                  8) 56226-07302-10008-16400-05504-46494
                  9) 59423-88222-19320-27513-74424-09512
                10) 16883-52659-08150-40350-17780-24261
                11) 96189-58076-21553-30924-38982-86863
                12) 33754-70851-61197-87733-71297-37640
                13) 12300-54253-90585-48410-09783-98342
                14) 97124-27134-10470-24310-39697-80781
                15) 03173-03811-97212-64023-45547-66064
                16) 01778-74321-32951-61616-17247-52405
                17) 40526-28860-35950-91199-21248-63794
                18) 87958-77693-98991-24981-92191-99421
                19) 85618-77154-61419-44003-34014-96741
                20) 20396-87420-02687-32166-48830-62633
                21) 88493-50806-21791-26339-72675-91691
                22) 18387-14516-68330-64658-08406-64312
                23) 94643-77372-05057-71446-23061-23523
                24) 53071-73890-66295-55786-53634-01284
                25) 98796-06709-25532-20825-78442-67851
                26) 20897-78967-87290-12054-71565-72490
                27) 97010-49681-46291-57323-65580-48976

 

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(If you happen get the exact same numbers as above well, that just proves my point.)
 

When you get a batch of these pseudo Random OTP-Key numbers you can copy and paste them into your Text  or Layout Program.  Then go back to the generator and create another batch if needed.  Keep doing this until you feel that you have enough to cover all of your message(s).  Please remember to never let it repeat itself within your message length.  (Please see OTP Batch Page Example.pdf.)

 

You can of course make the OTP-Key number groups different font sizes.  You can size them to fit on 8.5" x 11" sheets or very small for easier concealment.  Whatever that best suits your needs. 

 

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Communications Plan

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This is probably the most challenging part of all.  The printouts of the OTP-Key groups or batches should be labeled in some way so that they can be easily referenced by you and your intended recipients in order to be MATCHED UP with the correct messages.  For example message #5 needs to use OTP-Key Page #7 or message #6 will need to use OTP-Key Page #10 etc.  Maybe even using the SAME numbers for both Key and message might be a good idea.  Dating the tables might also help to avoid duplication.  Care should be taken in the communications plan because there could be so many ways to do this and presumably having a wide margin of error.

 

I would imagine that in the spy, military and diplomatic worlds, the communications plans can vary immensely.  For example, somewhere out in the ether of the shortwave radio bands, a 3-digit call-up number is being repeated for 10 minutes prior to the reading of the actual message.  Could that number be the number of the intended recipient?  Or is it the OTP Page number that the intended recipient must use to decipher his or her message?  Or could it simply be the message number itself and that the recipient would already know what key to use.  (Agent #980 received message #980 (containing 980 groups) and used Key #980 on 09/08/1980 at postal code 98000 Monaco from Postal Union-Local 980.)  Who knows?  Well of course somebody out there probably does.

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Finale! Finale!

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This is a partial example of the final product and what the public may see or hear:
 

"75467 65500 21447 72018 63137 67843 08225 50527 06508 78712 16573 98768..." etc.

 

Once you have your Ciphertext you can broadcast it, e-mail it, text it, blog it, publish it, print it out, hand-deliver it, snail-mail it, fax it, record it, carrier-pigeon it to your intended recipient(s).  (There is even a link below for posting it on a Numbers Relay Page.)

 

Your counterpart will then set up his or her worksheet and decipher your message and then send you a new one back!

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Have Fun!

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Thank you for visiting!

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Other Cool and Classic Old-School links:

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Chris Smolinski's Spy Numbers Stations on Shortwave Radio

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Ary Boender's Numbers & Oddities page

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Bob Grove's Monitoring Times

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Dirk Rijmenants' Cipher Machines and Cryptology

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The American Cryptogram Association or ACA

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The National Security Agency or NSA

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You can even post your own ciphers on the Numbers Relay Page (NRP)

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This site is dedicated In the Memory of

 

Tom Kneitel

 

W4XAA, K2AES, SK

 

(1933 - 2008)

 

Prolific author and editor emeritus of

Popular Communications magazine.

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This site was first published on 08-05-2001

Modified on 03-31-2024

 

© Copyright 2001-2023 WA4282SWL 

All rights reserved. 

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