Security model

Security and privacy design

classified follows a zero-knowledge pattern for one-time sharing: encrypt before upload, store ciphertext, reveal once, and delete the stored copy. This page explains the practical security properties and boundaries users should understand.

What the server stores

The server stores the encrypted payload and operational metadata needed to deliver and expire the share. It does not need readable note text or file contents to provide the service. This keeps accidental exposure, logging, and internal access risks lower than with plaintext sharing tools.

Key handling

For non-password shares, the decryption key is kept in the link fragment. For password shares, the recipient must know the password before the browser can decrypt the content. Lost links, lost passwords, or consumed shares cannot be recovered by MAIN OÜ.

Recommended use

• Send temporary credentials that will be rotated after use.
• Share short legal, finance, HR, or vendor notes without leaving them in chat history.
• Use a separate channel for passwords or verification when recipient identity matters.
• Avoid using one-time shares as your only copy of important records.

Limits

A recipient can still copy, screenshot, photograph, or forward what they see. One-time sharing controls storage on this service; it does not control the recipient's device or behavior.