Bisik only the two of you can hear it.
Private messages, end-to-end encrypted, for every Jianren user. A message is locked on your device and unlocked on your contact's device โ not even the server can read it.
What is Bisik? ๐คซ
Bisik is whispering in someone's ear, internet edition: only you and your friend can hear it. Our server is an illiterate mail carrier โ happily delivers sealed envelopes, physically cannot read them. Even if we got curious (we won't), all we'd see is alphabet soup.
How to use it โ 4 steps, no IT degree required ๐
Sign up & pick a nickname
Your nickname is your stage name. Your email is never shown to anyone.
Create your encryption key (one click)
Your device makes a secret key. Think of it like a toothbrush: yours alone, don't share it, and it never gets sent to us.
Save your BISIK1 backup code
Copy the backup code + passphrase somewhere safe. If you lose it, we truly CANNOT help โ not stingy, just mathematically impossible. ๐คท
Find your friend, start whispering
Type your friend's nickname โ chat away. Groups? Yes. Rocket stickers? Yes. Self-destructing messages like a spy movie? Absolutely โ the countdown starts when the message is READ, not when it's sent.
Prefer a blinking black screen? Install the terminal client below โ same concept, same keys.
Locked on your device
Your private key is generated and stored on your device โ it is never sent to the server.
The server is blind
The server only relays ciphertext (AES-256-GCM). Nobody can peek inside โ including us.
Safety number check
Compare safety numbers with your contact to be sure nobody slipped in the middle.
How does it work? ๐
- 1. Keys are born on your device. When you activate Bisik, your device generates an ECDH P-256 key pair (Web Crypto API). Only the public key is registered with the server.
- 2. The chat key is agreed on quietly. Your private key plus your contact's public key derive a shared secret (ECDH โ HKDF-SHA256) that is identical on both devices โ and never transmitted.
- 3. Every message is padlocked. Messages are encrypted with AES-256-GCM and a random IV before they leave your device; the server only stores & forwards the padlocked blob.
- 4. You can audit it yourself. The Safety Check page recomputes the key safety numbers on your device โ compare them with your contact over a call or face to face.
โ ๏ธ Honest about the limits: this version uses a single key pair per account (no forward secrecy like the Signal protocol yet), and if your key is replaced or lost, old messages can no longer be opened. Save an encrypted key backup from the "My Encryption Key" page before switching devices.
โจ๏ธ Bisik in your terminal
A standalone client for desktop & phones (via Termux) โ one file, nothing else to install, the same end-to-end encryption. Update any time with `bisik update`.
macOS ยท Linux ยท Android (Termux)
curl -fsSL https://jianren.cloud/bisik/install.sh | shWindows (PowerShell)
irm https://jianren.cloud/bisik/install.ps1 | iexBinaries are SHA-256 verified at install time. iPhone/iPad has no terminal โ use this web app, or SSH into your computer.