Cypher.

One zip per system; there is no installer. Unpack it anywhere and open Cypher. By downloading or using Cypher you agree to the Cypher licence agreement. Checksums: SHA256SUMS.txt.

Paying

1. Choose Download for your system, above. Your wallet opens — MetaMask, or any other Ethereum wallet in this browser — and connects if it has not yet.
2. Check the payment it shows you: $98, turned into ETH at Chainlink's ETH/USD rate at that moment, to 0x4F97D90D3A7d2E7f8FeD655dCa87438E910E422B on Ethereum.
3. Approve it in your wallet. The payment goes from your wallet straight to that address; your wallet adds the network's own fee.
4. The download starts once the network has confirmed the payment, usually within a minute.

You pay once. To download Cypher again, on another computer or when a new version is out, connect the same wallet on this page and sign in. Signing in is free and sends no transaction.

A payment on Ethereum cannot be reversed by anyone. If you paid and the download did not unlock, write to [email protected] with the transaction hash.

Getting started

1. Download the zip for your system, above. It is paid for from your wallet as you do: $98, once.
2. Unpack it into a folder of its own, anywhere you like, and keep that folder together:
   • Windows — right-click the zip and choose Extract All. Cypher does not run from inside the zip.
   • macOS — double-click the zip, then move Cypher to Applications.
   • Linux — unzip Cypher-1.0.1-linux-x64.zip -d Cypher
3. Open Cypher. It is not signed with a commercial certificate, so your system asks you to allow it, once:
   • Windows — open Cypher.exe. If you see "Windows protected your PC", choose More info, then Run anyway.
   • macOS — open Cypher. macOS blocks the first attempt: on macOS 15 and later, open System Settings → Privacy & Security, choose Open Anyway beside the message about Cypher, and confirm; on macOS 14, right-click Cypher and choose Open. If macOS says Cypher is "damaged", that is the download's quarantine flag, not a broken file: run xattr -dr com.apple.quarantine /Applications/Cypher.app in Terminal.
   • Linux — run Cypher/cypher. On Ubuntu 24.04 and later it stops with a message about the SUID sandbox helper; run once, in the Cypher folder, sudo chown root:root chrome-sandbox && sudo chmod 4755 chrome-sandbox, then start it again.
4. Accept the licence agreement. Cypher shows it before anything else. Choose I agree to start using it.

The same steps travel inside the Windows and Linux zips, in README.txt. To update, replace the folder (on a Mac, the app) with the new version's; to remove Cypher, delete it.

What is inside

• Advanced — educational. File Analyzer, Encryptor, Decryptor, File Recovery. Real AES and 3DES beside teaching ciphers, to see how encryption works. No integrity protection: not for real secrets, and every tab says so.
• Military — real. Secure Encryptor and Combat Decryptor: AES-256-GCM authenticated encryption, the key derived from your password with Argon2id.
• Quantum — real. Quantum Vault and Quantum Unseal: a hybrid seal, ML-KEM-1024 with X25519, signed with ML-DSA-87 and Ed25519. Secret Sharing splits a secret into shares of which any chosen number rebuild it. Security Lab runs nine attacks against freshly sealed vaults, live.

A sealed file is as strong as its password, and there is no recovery if the password is lost. Military and Quantum files are limited to 8 MiB, Secret Sharing to 1 MiB.

Check your download

Before running a download, compare its SHA-256 checksum with the one shown under its button above, or in SHA256SUMS.txt:

• Windows (PowerShell): Get-FileHash .\<file>
• macOS: shasum -a 256 <file>
• Linux: sha256sum <file>

If they differ, delete the file and do not run it.

Privacy

Cypher runs entirely on your computer. It does not send your files, passwords, keys or any information about you to us or to anyone, it has no account, and it collects no usage data. It makes no network connections at all.

That covers the app. This website counts visits with Cloudflare Web Analytics, which uses no cookies. Buying sets one cookie, which is how the site knows that this browser has paid. The record of a purchase holds the wallet address and the transaction that paid, both public on Ethereum already, and no name, email or card.

Licence

Cypher costs $98, paid once. It is © 2026 Nem088, all rights reserved, and licensed under the Cypher licence agreement: you may install and use it on your own devices, but not copy, share, resell, modify or reverse-engineer it. Download it only from this page. Open-source components included in Cypher are listed in THIRD_PARTY_NOTICES.txt, inside the app.

There is no automatic update. A new version appears on this page; the app's About page shows the version you have.

Support

Questions and security reports: [email protected]