FILECHAT
2025A peer-to-peer, end-to-end encrypted, serverless web chatroom. Key exchange runs over ECDH P-256, messages are sealed with AES-GCM, and there is no host in the middle. It self-updates with cryptographic signatures.
Try FILECHAT-
1. Pick a curve
Both sides agree on the same elliptic curve up front. P-256 is the standard safe pick, and the curve is fully public. The secrecy comes later.
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2. Private numbers
Alice picks a random integer
a, Bob picksb. These are the secrets of the handshake. They never leave the machine that generated them. -
3. Publish
Each side multiplies the base point
Gby their private. Alice sendsA = aG; Bob sendsB = bG. Both points cross the wire in plain view. -
4. Mix
Each side multiplies the received point by its own private. Alice gets
aB, Bob getsbA, and both land on the same curve point. Nobody on the wire can produce it without one of the two privates. -
5. Derive
The shared point gets hashed through SHA-256 into a clean 256-bit key. AES-GCM takes it from there. Every byte on the wire is encrypted and authenticated.
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6. Eavesdropper
Mallory sees both
AandBon the wire. To get the key she needsafromAorbfromB. That's the elliptic-curve discrete-log problem; on P-256, nobody knows how.