valerio-vaccaro/nato_encoder

Encode hexadecimal string using nato alphabet

Nato Encoder

Encode hexadecimal string using the nato alphabet/numbers.

python3 nato_encoder.py encode -M "deadbeef" -f "result.wav"

zero zero one four uniform two whiskey four three six

The file result.wav contain an audio version of the result phrase (created locally).

You can decode the nato string in the same manner.

python3 nato_encoder.py decode -M "zero zero one four uniform two whiskey four three six"

deadbeef

The -h argument can help you understanding how this program is working.

usage: nato_encoder.py [-h] {encode,decode,map,version} ...

NATO alphabet encoder/decoder.

positional arguments:
  {encode,decode,map,version}

optional arguments:
  -h, --help            show this help message and exit

Protocol

The protocol uses a starting code (2 chars of start type) followed by the message encoding. The encoding is realized char by char with a different conversion table for even and odd characters, this technique allows to recognize easily if a char is missing in the sequence.

Even chars

Fist nibble of the byte is encoded with a set of nato chars:

• 0: alpha
• 1: charlie
• 2: echo
• 3: golf
• 4: india
• 5: kilo
• 6: mike
• 7: oscar
• 8: quebec
• 9: sierra
• a: uniform
• b: whiskey
• c: yankee
• d: one
• e: three
• f: five

Odd chars

Second nibble of the byte is encoded with a different set of nato chars:

• 0: bravo
• 1: delta
• 2: foxtrot
• 3: hotel
• 4: juliett
• 5: lima
• 6: november
• 7: papa
• 8: romeo
• 9: tango
• a: victor
• b: xray
• c: zulu
• d: two
• e: four
• f: six

Special chars

• start: zero - used two time as starting sequence,
• silence: char not printed but used as separator between words (in audio).

Dependencies

• pydub used for create an unique wav file,
• speech_recognition used for STT conversion.

License

           GNU GENERAL PUBLIC LICENSE, Version 3

Based on pgp-words.py Copyright (C) 2015 Joe Ruether [email protected]