Columnar Transposition Encryptor

Ragged unpadded stable alphabetical key column transposition, row-major input, no fabricated cells. Classical educational encoding only; not secure encryption, no hidden normalization or inferred key.

Description

Columnar transposition reads columns in key-defined order.

Columnar transposition reads columns in key-defined order.^[1]

Duplicate key letters need a stable tie convention to make a ragged grid reversible. Use Columnar Transposition Encryptor to evaluate the supplied inputs under the specific model below.

When to use Columnar Transposition Encryptor

Use Columnar Transposition Encryptor 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 Columnar Transposition Encryptor 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 using the field table and validation rules below, then run the tool.
Read Transformed 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

Enter uppercase A–Z text and a nonempty uppercase key of at most 128 letters. Stable alphabetic key sorting orders columns, with duplicate key letters tied left to right. Write text row-major and read columns in that order without padding. Ragged final rows and empty text are accepted; no normalization or modern confidentiality is provided.

ciphertext = concatenate ragged columns in stable alphabetical key order

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

Output field	Meaning	Value type
transformed	Transformed	string

json

{
  "input": {
    "text": "ABCDE",
    "key": "BA"
  },
  "output": {
    "transformed": "BDACE"
  }
}

Limitations and assumptions

Duplicate key letters need a stable tie convention to make a ragged grid reversible. 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 Route Spiral Transposition Tool for a related task: A spiral route reads cells around a filled rectangle in a chosen direction.

Use Transposition Column-Count Candidate List for a related task: A column-transposition hypothesis assigns text to a rectangular or ragged grid.

References

Columnar Transposition Encryptor — tool.io

Similar or alternative tools

Route Spiral Transposition Tool
A spiral route reads cells around a filled rectangle in a chosen direction.
Transposition Column-Count Candidate List
A column-transposition hypothesis assigns text to a rectangular or ragged grid.