Encrypt anything. Change every setting.
Most encryption tools give you one button and hide everything behind it. This one gives you the whole panel — the cipher, the mode, the key size, the derivation function and every cost knob it has — and then shows you what each choice did to the bytes.
LEUMAS ENCRYPT // THE WHOLE PANEL
One button is not a tool.
Every encryption app gives you a padlock and hides the rest. You get a file back and no idea what happened to it.
This one hands you the panel: the cipher, the mode, the key size, the derivation function and every cost it has.
- 8
- cipher suites
- 3
- key derivations
- 8
- cost parameters
01 / WHERE IT RUNS
Your file never leaves the room.
The lab runs in your browser. The bytes go from the file picker into the tab and back out to your downloads, and no part of that route passes through us.
Which means there is no upload, no size limit, no queue, and nothing on our side that could be read even if somebody wanted to.
- 6
- suites run locally
- 0
- bytes uploaded
02 / THE PARAMETERS
Change a number. Watch the bytes move.
Raise scrypt's cost from 16,384 to 262,144 and feel the derivation take a second instead of a tenth of one. That second is what an attacker pays for every guess.
Encrypt the same file twice with the same passphrase and get two results that share no bytes. That is the random salt doing its job, and you can see it.
03 / WHAT IT DOES NOT DO
It will not lie to you.
Turn authentication off and change one byte of the result: the file decrypts, silently, to something wrong. That is the lesson, and it is a switch rather than a paragraph.
The container header is plain text and says so — it records which cipher you chose, and it records your filename only if you ask. A tool that hid that would be hiding the interesting part.
04 / THE FILE
It carries its own instructions.
Every parameter you chose is written into the file. Send it to yourself in a year, having forgotten all of them, and the passphrase alone still opens it.
The same file opens in Studio, over the API and from a script, because they are all the same engine.
Questions
- Does my file get uploaded?
- Not by default, and that is the whole design. The lab runs in your browser over the Web Crypto API, so the file and the passphrase never leave your device — there is no size limit because there is nothing to upload. A server lane exists for the few algorithms a browser genuinely cannot run, and the lab tells you which lane it is about to use before it uses it.
- Can Leumas read what I encrypt?
- On the browser lane there is nothing to read — the work happens in your tab and we never see the bytes. On the server lane the file and the passphrase are held in memory for the length of one request, never written to disk and never logged. That is the honest limit of any server lane, and it is why the browser one is the default.
- What happens if I forget the passphrase?
- The file is gone. There is no reset, no recovery and no copy of your key anywhere — that is what makes it encryption rather than storage. Write the passphrase down somewhere real before you encrypt anything you cannot afford to lose.
- Will the file open somewhere else?
- It opens anywhere Leumas Encrypt runs — this site, Leumas Studio, the API and the command line — because the format records the cipher and every cost parameter inside the file. It is not PGP or an encrypted ZIP, so another program will not read it.
- Why do some options say "server only"?
- Because a browser cannot run them. Chrome refuses 192-bit AES keys, the Web Crypto API has no ChaCha20 and no scrypt, and Argon2 is a native binary. We fixed the scrypt gap ourselves so the default works locally; the rest are shown, disabled, with the reason attached rather than quietly removed.
- Do I need a membership?
- For the lab, yes — any active Leumas membership, or an admin account. Everything on this site that explains how the algorithms work is free and always will be.