High-security ciphers that can be done by hand, coded in JavaScript
This page contains a number of JavaScript-coded files that demonstrate different encryption methods that are human-computable. They require only pencil and paper, plus maybe a ready-made Tabula Recta or a set of Scrabble tiles. Fairly long articles on the different ciphers can be found at my blog: https://prgomez.com
Here's a list of the files and what they do (LFG means lagged Fibonacci generator):
Aphid.html: transpositions plus Polybius square encoding
Arsenio.html: transpositions plus straddling checkerboard encoding
BookPad.html: straddling checkerboard encoding plus adding multi-layered long text
DicePad.html: 6-sided Polybius square encoding plus von Neumann extractor
FiboFile.html: Fibonacci RNG in base64
FibonaRNG.html: Fibonacci RNG on letters
FilePad.html: different methods applied to a file (binary)
FileSkink.html: Skink in base64
FileSnake.html: Snake in base64
FileWorm.html: Worm in base64
FileZag.html: Zigzag in base64
Fileacci.html: transpositions plus LFG applied to a file (binary)
Fileine.html: Serpentine in base64
Filenaire.html: Visionnaire in base64
HalfScrabble.html: Scrabble with only one alphabet set
LetterPad.html: base 24 von Neumann extractor
Letteracci.html: adding single-layer long text randomized by LFG
Numeracci.html: straddling checkerboard plus single-layer LFG-randomized long text
PasswordPrava.html: password generation from a challenge text, using a tabula Prava with 2 substitution alphabets
PLhuman.html: version of FibonaRNG implemented into PassLok; has a method to add spaces and punctuation, plus error correction
PolyCrypt: more secure cipher evolved from PLhuman; can emulate classic ciphers as well
README.md: this file
Scrabble.html: simplified ChaoCipher algorithm using two Scrabble tile alphabets
Serpentine.html: 5-letter autokey using Tabula Recta
Skink.html: 4-letter serpentine autokey using Tabula Recta
Snake.html: 4-letter serpentine operations to add triple-length long key
Subtracci.html: Triple Text using simpler subtractions rather than additions, but not chained as in Snake
SuperAphid.html: Aphid plus transposition
SuperFileine.html: Fileine plus transposition
SuperSerpentine.html: Serpentine plus transposition
SuperSkink.html: Skink plus transposition
SuperVisionnaire.html: Visionnaire plus transposition
SuperWorm.html: Worm plus transposition
TripleText.html: adding triple-layer long text
Visionnaire.html: 2-letter autokey using Tabula Recta
Worm.html: 4-letter autokey/Vigenere using Tabula Recta
Zigzag.html: 3-letter autokey using Tabula Recta
alphabet.html: uses serpentine operations to make mixed alphabet from a long piece of text