Nihilist Substitution Tool

Explicit Nihilist two-digit row/column numeric sum, no mod100 wrap or hidden J merging. Classical educational encoding only; not secure encryption, no hidden normalization or inferred key.

Description

Nihilist substitution adds coordinate numbers for message and key symbols.

Nihilist substitution adds coordinate numbers for message and key symbols.^[1]

The supplied square and repeated key define the historical variant. Use Nihilist Substitution Tool to evaluate the supplied inputs under the specific model below.

When to use Nihilist Substitution Tool

Use Nihilist Substitution 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 Nihilist Substitution 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, Key, Caller square using the field table and validation rules below, then run the tool.
Read Encoded numbers 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
key	Key	string	Required; constraints below
callerSquare	Caller square	string	Required; constraints below

Enter a 25-symbol uppercase-letter/digit permutation, text drawn from it and a nonempty key drawn from it. Convert text and repeated key symbols into one-based row-column numbers 11 through 55, then add them as ordinary integers. Return one number per text symbol; no modular reduction or decoding operation is provided.

cipherNumber[i] = polybiusNumber(text[i])+polybiusNumber(key[i mod keyLength])

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

Output field	Meaning	Value type
encodedNumbers	Encoded numbers	array of number

json

{
  "input": {
    "text": "ABC",
    "key": "BC",
    "callerSquare": "ABCDEFGHIKLMNOPQRSTUVWXYZ"
  },
  "output": {
    "encodedNumbers": [
      23,
      25,
      25
    ]
  }
}

Limitations and assumptions

The supplied square and repeated key define the historical variant. 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.

Alternative or Complementary methods

Use AD FGX Cipher Tool for a related task: ADFGX combines five-by-five coordinate substitution with keyed column transposition.

Use Polybius Square Coordinate Lookup for a related task: A Polybius square maps symbols to row and column coordinates.

References

Nihilist Substitution Tool — tool.io

Similar or alternative tools

AD FGX Cipher Tool
ADFGX combines five-by-five coordinate substitution with keyed column transposition.
Polybius Square Coordinate Lookup
A Polybius square maps symbols to row and column coordinates.