We believe sensitive information deserves better than email threads and Slack messages. CipherOnce was built to make secure, ephemeral sharing as easy as copying a link.
Every day, developers, teams, and individuals share passwords, API keys, and confidential notes through email, Slack, Discord, and SMS. These platforms were never designed to carry secrets — they store everything indefinitely, replicate messages across servers, and expose your data to breaches that may not surface for years.
The average data breach exposes credentials shared months or years prior. Traditional "secure" sharing services claim safety, but many process your plaintext on their servers — creating a single point of failure that attackers actively target.
"Sending a password over chat is like writing your house key on a postcard. It might arrive safely — but you'll never know how many people read it along the way."
Encryption and decryption happen entirely in your browser using AES-256-GCM. The raw plaintext never leaves your device and never touches our servers — not even for a millisecond.
The decryption key lives in the URL fragment (#) — a part of the URL that browsers never send to servers. We store only encrypted ciphertext. We are architecturally incapable of reading your secrets.
Every secret is configured with a view limit and expiry. Once conditions are met, the encrypted record is permanently deleted — no backups, no archives, no recovery. Gone means gone.
We built CipherOnce because the tools most people use for sharing secrets treat security as an afterthought. Privacy shouldn't require a PhD in cryptography or an enterprise budget. It should be the default.
CipherOnce is open source, requires no account for basic use, and is built on verifiable cryptographic principles rather than marketing promises. Our architecture is designed so that even if we wanted to read your secrets — we cannot. That's not a policy. It's physics.
Whether you're a solo developer sharing API keys, an enterprise team managing credentials, or an individual protecting personal information, CipherOnce gives you the same military-grade protection without the complexity.
AES-256
Encryption standard
0 bytes
Plaintext stored
100%
Client-side encryption
Open
Source code
Why CipherOnce is a more secure, privacy-first alternative to traditional one-time secret services.
Best practices for sharing credentials and how CipherOnce's zero-knowledge model protects them.
The technology behind ephemeral messages and why true destruction requires zero-knowledge architecture.
A technical deep-dive into how CipherOnce ensures we are structurally incapable of reading your data.
How your browser encrypts secrets before they ever leave your device — and why that makes all the difference.
We cannot read your secrets — not by policy, but by architecture. A full breakdown of what we store and don't.
