Introducing Paper: Docs That Actually Respect Your Privacy

Paper is our new document editor. It is a full rich text editor inspired by Google Docs and Proton Docs, and it is built on PlateJS.

What Paper is

Paper is a familiar editor for writing and collaborating on documents. It focuses on speed, reliability, and a clean writing experience. It supports headings, lists, code blocks, inline formatting, and embeddable blocks for images and links.

Paper opens inside your Drive workspace and saves to your account just like files. Documents behave like other Drive items: you can move them, share them, or export them.

Quick start

1. Open Drive and click New → Paper.
2. Give it a title and start writing. Your changes are saved automatically.
3. Share with collaborators or export as Markdown or PDF.

For developers and nerds

Paper is built on PlateJS, a plugin-based editor built on top of Slate. That means:

• A compact core with plugin-driven features.
• Easy to extend with custom blocks or behavior.
• Familiar Slate model for those who have built rich editors before.

Privacy and storage

Documents are private by default. Paper files are stored in your Ellipticc Drive account and follow the same access and sharing rules as other files.

Fast, private editing

Papers are treated exactly like files. Semantically a Paper is a list of blocks, not one huge file. Updating a single character usually touches a single block, which keeps the change small, typically a few kilobytes, even with encryption in place. That design makes Paper feel fast and responsive despite a crypto-heavy client.

Block-level diffing

• Each block is hashed (SHA-256) and the hash is used to detect changes.
• The PaperService only encrypts and uploads blocks that are new or changed.
• Encryption is done with XChaCha20-Poly1305 and each block stores its nonce and salt so the client can decrypt later.

The result: edits feel as fast as a standard collaborative editor because we avoid re-encrypting the whole document on every save.

Key derivation and encryption (short)

• Master Key: derived from your password using Argon2id (we use hash-wasm in the client).
• Block keys (CEKs): for every block we derive a unique content encryption key from the Master Key and a random 32-byte salt via HMAC-SHA256. This isolates blocks: compromising one block’s key does not break the rest.
• Encryption: Blocks are encrypted with XChaCha20-Poly1305; the ciphertext includes a nonce and the salt used for key derivation.

Yes, even filenames and emoji are encrypted. Paper keeps the interface familiar while ensuring your data stays private.