AD FGX Cipher Tool

Explicit AD FGX caller-square coordinate substitution then stable keyed ragged column transposition. Classical educational encoding only; not secure encryption, no hidden normalization or inferred key.

Description

ADFGX combines five-by-five coordinate substitution with keyed column transposition.

ADFGX combines five-by-five coordinate substitution with keyed column transposition.^[1]

The caller square and stable key ordering define the encoded stream. Use AD FGX Cipher Tool to evaluate the supplied inputs under the specific model below.

When to use AD FGX Cipher Tool

Use AD FGX Cipher Tool to evaluate the supplied inputs under the specific model below. Choose the intended encoding, alphabet or check and keep the exact character, key and measurement conventions described below.

How to use AD FGX Cipher Tool and understand its results

Choose the intended encoding, alphabet or check and keep the exact character, key and measurement conventions described below.
Enter Text, Caller square, Key using the field table and validation rules below, then run the tool.
Read Encoded and interpret units, signs, ordering and placeholders as explained below.
If the tool reports an input error, correct that field and rerun. A successful false result, empty match list or unknown-evidence placeholder has the specific meaning described here; check the limitations before applying the result.

Input field	Meaning	Value type	Requirement
text	Text	string	Required; constraints below
callerSquare	Caller square	string	Required; constraints below
key	Key	string	Required; constraints below

Enter text drawn from an exact 25-symbol permutation of uppercase ASCII letters or digits and a nonempty uppercase A–Z column key of at most 128 letters. Map each symbol to ADFGX row and column labels, then apply ragged columnar transposition with stable alphabetic key sorting and duplicate ties left to right. No padding or decoding is supplied. The coordinate stream must fit the transpose helper's 4096-character limit, so text longer than 2048 symbols is rejected even though the original text field permits 4096.

ciphertext = columnarTranspose(ADFGX coordinate pairs, stableSortedKeyColumns)

Field order, units and branch conditions follow the implementation explanation above.

Output field	Meaning	Value type
encoded	Encoded	string

json

{
  "input": {
    "text": "ABC",
    "callerSquare": "ABCDEFGHIKLMNOPQRSTUVWXYZ",
    "key": "BA"
  },
  "output": {
    "encoded": "ADFAAA"
  }
}

Limitations and assumptions

The caller square and stable key ordering define the encoded stream. Apply the exact scope and assumptions described above.

All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are stated above; extremely large inputs or outputs can also be rejected. These errors differ from successful results such as false, no matches or unknown evidence.

This educational transformation or format check does not establish modern cryptographic confidentiality, authentication or key security.

Alternative or Complementary methods

Use AD FGVX Cipher Tool for a related task: ADFGVX uses a six-by-six symbol square before keyed column transposition.

Use Nihilist Substitution Tool for a related task: Nihilist substitution adds coordinate numbers for message and key symbols.

References

AD FGX Cipher Tool — tool.io

Similar or alternative tools

AD FGVX Cipher Tool
ADFGVX uses a six-by-six symbol square before keyed column transposition.
Nihilist Substitution Tool
Nihilist substitution adds coordinate numbers for message and key symbols.