Substitution (Solve)

Substitution ciphers are those types where individual characters of the plaintext are replaced by another character and arranged in the same order. For a description of the ciphers go to the Substitution (Create) menu pages on this site.

The colored outline around a box indicates if the option is required or not.
  • Red border - Mandatory. These appear before the ciphertext box on the page. Most of these fields are pre-populated.
  • Blue border - Optional. Used to submit known keywords to solve a cipher.
Select a language
Select from the drop down menu the plaintext language. This loads the appropriate language data. Default is English

Use accented characters
Enables the use of accented, or diacritic, characters in plaintext. Only used in the Monoalphabetic Substitution solver and with German, Spanish, Norwegian, Swedish and Danish languages.

Number of threads to use
Select the number of threads or cores/processors the program should use and this may help to find a solution quicker. The options available depend on the number of cores on your system. The number of threads available for CryptoPrograms is less than the number available to prevent a user accidentally slowing their machine too much. The default is 1.

Enter cipher text to be deciphered
Field for the ciphertext. Invalid characters for a particular cipher type will be ignored.

'Solve Cipher' button
Starts the search for a solution.

'Stop Solving' button
Stops the search for a solution.

Enter maximum number of best solutions to display
Enter the number of best matches to display, up to a maximum of 100. Default is 10.

Best solution
The solution is in the form:
SolutionNo.  Score - Key: Solution
Also displayed is the time taken to find the best match so far and the total time taken.
Scores for the plaintexts are calculated from the frequency of tetragraphs in the selected language.

Sample solution

1  737 - DBCEA: toomuchdiscussionespeciallyofgreatthingstendstomakethemappearsmallerlimitsthem
2  469 - DBDEA: tonmuchciscursiondspechallynfgreztthimgstemdstolaketgemapoearslalleqlimissthel
3  457 - DFCEA: tkomucddiscqssiojespeyialluofgraatthengstandstkmakephemalpearomallarlimetstham
4  436 - HBCEA: poomuyhdisyussiknespacialhyofgneattdingspendspomakathemwppeansmalherliiitstdem
5  424 - DBAEA: toqmuchfiscuusiongspeckallyqfgrectthipgstepdstooaketjemaprearsoalletlimivstheo
Time taken: 1.443 seconds.
Total running time: 1.84 seconds.

1. Monoalphabetic Substitution also known as Aristocrat, Patristocrat or Simple Substitution