Hash or lock a file
Fingerprints
| Algorithm | Fingerprint | |
|---|---|---|
| MD5128 bits | ||
| SHA-1160 bits | ||
| SHA-256256 bits | ||
| SHA-384384 bits | ||
| SHA-512512 bits |
MD5 and SHA-1 are fine to check a download, not to protect against someone forging a file.
No match.
Password lock
Longer is stronger: four unrelated words beat a short password full of symbols. There is no way to recover a forgotten password: keep it safe.
How it works
Fingerprints: type a text or drop a file, and its MD5, SHA-1, SHA-256, SHA-384 and SHA-512 fingerprints appear at once. Paste the fingerprint published by the author in the check box: if it matches one of them, the file is exactly the original. Password lock: choose Lock, a message or a file, and a password; the message becomes a block of text to copy, the file a .locked file to download. To read it back, choose Unlock, give the block or the file and the same password. Everything happens in your browser.
Questions
Are my files or my password sent anywhere?
No. Fingerprints and encryption are computed by your browser’s built-in cryptography; the page is not allowed to contact any other site, and neither the files nor the password are saved.
What is a fingerprint (checksum) for?
It is a short code computed from every byte of a file: change one byte and it changes completely. Software sites publish the SHA-256 of their downloads; paste it in the check box to be sure your copy is complete and was not altered. Upper or lower case and spaces around it do not matter.
How strong is the lock?
It uses AES-256-GCM, the standard used by banks and messaging apps, with a key derived from your password by PBKDF2 (600,000 rounds of SHA-256) and a random salt every time. Without the password, the content cannot be read, and any change to the locked data is detected. Its real strength is your password’s: the meter helps you choose a long one.
I forgot my password: can I get my file back?
No. Nobody keeps a copy of it, not even this site, and that is what makes the lock safe. Keep the original until you are sure the locked copy opens, and store the password somewhere safe (a password manager).
How do I send a locked message to someone?
Lock it, copy the block of text and send it by e-mail or chat; give the password another way (a call, in person). The recipient opens this page, chooses Unlock, pastes the block and types the password. Files work the same way with the .locked file.