Blink
by MALTO

Share secrets that disappear. Once seen, forever gone.

About Blink

Secure secret sharing,
built the right way.

Blink lets you share passwords, API keys, files, and sensitive text through a one-time link that permanently self-destructs the moment it is opened. No accounts. No database. No trace.

Create a Secret

How it works

Phase 1: Create
1
You enter your secret
Type or paste your password, API key, or any sensitive text directly in your browser. Nothing is sent yet.
2
Browser encrypts it
Your browser generates a random AES-256-GCM key K and encrypts the secret locally. The plaintext never leaves your device.
3
Key is split in two
K is split into K1 (random bytes) and K2 (K XOR K1). K1 goes into the URL fragment, which the browser never sends to any server. K2 is sent to the server.
4
Server stores everything masked
The server masks K2 with HMAC(K3, id) before storing it, and re-encrypts the ciphertext with K4. K3 and K4 are permanent server secrets that never travel over any network.
5
You get a one-time link
The link contains K1 in the URL fragment. Share it via WhatsApp, email, or any channel. Optionally lock it to a recipient's email with a 6-digit OTP.
Recipient opens the link
Phase 2: Reveal
6
K1 is read and erased
The recipient's browser reads K1 from the URL fragment and immediately clears it from browser history, before any network request is made.
7
OTP verified (if set)
If a recipient email was set, the server asks for the 6-digit code. Five wrong attempts permanently destroys the secret. Correct code proceeds to decryption.
8
Server reconstructs and decrypts
Using K1 + K2_stored + K3 + K4, the server reconstructs K, unwraps the ciphertext, and decrypts the secret. All four factors are required; missing any one makes decryption impossible.
9
Secret shown, deleted forever
The plaintext is returned to the browser and the secret is permanently deleted from server memory in the same atomic operation. The link is now dead forever.

What makes it secure

Four-factor key splitting
K1 (URL) + K2 (server memory) + K3 (HMAC mask) + K4 (ciphertext encryption). All four required. Missing any one means decryption fails completely.
View once, gone forever
Secret is deleted from memory atomically on first reveal. No database, no backup, no log. Even we cannot retrieve it after deletion.
No offline decryption
Even with the ciphertext and the URL, decryption is impossible without the server. K2, K3, and K4 never leave the server.
Email OTP lock
Lock a secret to a specific inbox. Recipient must enter a 6-digit code. Five wrong attempts permanently destroys the secret.
Auto-expiry
Unviewed secrets are automatically purged at your chosen expiry (1 hour to 48 hours, or 7 days with Pro). The link becomes permanently invalid with no manual action needed.
Strict CSP & no tracking
No external scripts, no fonts, no analytics. Content Security Policy blocks all injection. User content is set via textContent, immune to XSS.

Blink Pro

Blink is free forever: view-once secrets, files up to 2 MB, email verification, and expiry up to 48 hours. Pro adds flexibility for $3.99/month, cancel anytime. No account needed, just a license key.

Files up to 25 MB
Share documents, configs, exports, and archives. Encrypted in your browser before upload, exactly like text secrets.
7-day expiry
Give recipients up to a week to open your link instead of 48 hours. Perfect when they are traveling or in another timezone.
Multi-view links
Allow up to 5 views on one link, ideal for sharing with a small team. The secret is destroyed after the last allowed view.
Passphrase protection
Add a passphrase the recipient must enter, shared through a separate channel. Five wrong attempts destroys the secret.
View notifications
Get an email the moment your secret is revealed, with the number of views remaining. Proof of delivery for sensitive handoffs.
Same privacy model
Pro changes limits, not the crypto. No account is created and the four-factor key splitting applies to every secret, free or Pro.
Free
$0forever
  • Text secrets up to 10 KB
  • Files up to 2 MB
  • View once, then gone
  • Expiry up to 48 hours
  • Email code verification
  • End-to-end encryption
Free forever
PRO
Pro
$3.99/ month
  • Everything in Free
  • Files up to 25 MB
  • Expiry up to 7 days
  • Multi-view links (up to 5 views)
  • Passphrase protection
  • Email notification when viewed

Frequently Asked Questions

Yes. The moment the recipient opens the link and reveals the secret, it is permanently deleted from the server's memory. There is no database, no backup, no log. Once gone, not even we can recover it. With a Pro multi-view link, deletion happens after the last allowed view instead of the first.
No. Your secret is encrypted in your browser before anything is sent to the server. The server only ever sees ciphertext, never plaintext. Even if the server were compromised, the attacker would need all four cryptographic keys to decrypt anything. And even if we somehow could read your secret, we would have no idea who sent it: no accounts, no names, no identity.
The AES-256 key K is split: K1 goes in the URL fragment (never sent to the server), K2 is sent to the server but masked with HMAC(K3) before storage, and the ciphertext is re-encrypted with K4. K3 and K4 are permanent server environment variables that never travel anywhere. All four are required to reconstruct K and decrypt.
Unviewed secrets automatically expire at your chosen time (1, 6, 24, or 48 hours, or 7 days with Pro). Once expired, the secret is purged from memory and the link becomes permanently invalid. Nothing is kept.
Optionally, you can lock a secret to a specific recipient by entering their email address. They will receive a 6-digit one-time code that they must enter before the secret is revealed. Enter 5 wrong codes and the secret self-destructs permanently.
No. Once you share the link, consider the secret gone. If you open it yourself, it will be deleted and the recipient will not be able to view it (on a Pro multi-view link, opening it consumes one of the allowed views). Simply create a new link if needed.
Yes. The decryption key is in the URL fragment (the part after the #), which is never sent to any server. Even if intercepted, the link works only once. For maximum security, combine it with email OTP.
Anything text-based: passwords, API keys, private notes, credentials, access codes, recovery phrases (up to 10 KB). You can also share files up to 2 MB (25 MB with Pro), encrypted in your browser before upload. Executable and script file types are blocked for safety. And the built-in password generator creates a strong password you can share instantly.
Pro unlocks 25 MB files, 7-day expiry, multi-view links, passphrase protection, and view notifications for $3.99/month. There is no account: after checkout you receive a license key by email, paste it once into Blink, and Pro is active in that browser. You can cancel anytime and keep using the free plan forever.
Yes. The full source code is on GitHub under the AGPL-3.0 license, so anyone can audit the encryption instead of taking our word for it. You can also self-host Blink on your own server for free.