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Zas addresses files by their content, not by who uploaded them. If a file already exists anywhere in the system, your send completes in about one second, no matter how large the file is. Two gigabytes can move in zero seconds.

How it works

When you send a file, Zas checks whether that exact content already exists in the network. If it does, the system skips the upload and creates a reference to the existing encrypted data. You still hold the only decryption key. The result is instant delivery without duplicate storage.

Blind key derivation

Zas uses OPRF (Oblivious Pseudo-Random Function) for blind key derivation. Your client derives a key from the file content without revealing the content hash to the server. The server never sees what you are sending, and it cannot tell whether two users share the same file.
Global dedup is invisible to you. It just means large files arrive faster and the system stays efficient.