Questions about the site

Do I need an account?

No. You can browse Challenges, use the Workbench, and check a Flag without one. An account is only needed if you want Decipher to remember saved and completed Challenges.

Is Decipher free, and will it stay free?

Yes, it is free today. My plan is to keep the Workbench and a substantial catalog of Challenges free. I may add optional paid Challenge packs later.

Is Decipher associated with an organization?

No. Decipher is my independent project. Source links, citations, and familiar cipher terminology do not mean that an archive, publisher, club, or any other organization is involved with or endorses the site.

Does Decipher follow an organization's cipher rules?

I use established terms such as Aristocrat and Patristocrat as accurately as I can, but Decipher does not claim strict conformance to any organization's rulebook. When a convention matters to a particular Challenge, I try to say so.

What is a Flag?

A Flag is the text Decipher checks when you think you have solved a Challenge. It is usually the first 64 significant characters of the recovered message, or the whole message when it is shorter. The exact rule is shown beside the Flag field.

What does Decipher save?

With an account, Decipher remembers which Challenges you saved and completed. It does not currently save the contents of your Workbench.

Does the Workbench solve the cipher?

That is not what it is for. The tools handle counting, rearranging, comparison, transformation, and keeping track of hypotheses. Choosing what to try—and deciding what the result means—is left to you.

Can I use outside tools?

Absolutely. Use pencil and paper, your own programs, other websites, or anything else that helps.

Are automatic solvers allowed?

Yes. I am not going to police how anyone solves a puzzle. Decipher is designed for people who want to do the reasoning themselves, but automatic solvers are allowed.

Does Decipher use AI?

Very much so. Decipher would not have been possible for me to build at this scale without AI, and I use it heavily while developing the site. In the long run, however, I want as little of the published text as possible to be AI-written. Historical notes, explanations, and Challenge text should be checked, rewritten, and increasingly written by people.

What do Featured, Tutorial, and Activity mean?

Featured is simply a changing selection of Challenges I think are worth showing. Tutorial means the Challenge is intended to teach a method. Activity is the number of accounts that have completed it.

Where do the Challenges come from?

They are a mix of historical material, adaptations, and puzzles written for Decipher. I try to give each Challenge a clear origin and solution status, with links to archival or research sources where they exist.

Are historical Challenges reproduced exactly?

Not always. I preserve historical ciphertext as closely as the sources permit, but some material is adapted or reconstructed. I try to state the origin, source, solution status, and any changes that matter to solving on the Challenge page.

Can a Challenge be unsolved?

Yes. Some famous ciphers still have no accepted solution. Decipher marks those Challenges with an unknown solution status and does not give them a Flag to submit.

Can I submit a Challenge?

Not yet. For now, Challenge Author access is limited to trusted operators.

Found a technical error, factual mistake, or disputed reading? Write to contact@decipher.nu.