EFShare

What is EFShare?

EFShare is an open-source web application designed for direct peer-to-peer file distribution without central data storage intermediaries. Systems engineers, media producers, and software developers use EFShare to move files ranging from 10 megabytes to several gigabytes directly across local area networks or the wider internet. The system accepts any digital payload from a local storage device—such as system images, disk backups, or high-definition video archives—and processes it through browser memory. The resulting output is a raw binary stream delivered straight into the remote peer's browser environment, assembling the file on their target file system upon arrival. First, it utilizes browser-native WebRTC DataChannel protocols to negotiate socket connections directly between client nodes. Second, it applies client-side AES-GCM 256-bit cryptographic encryption, ensuring that data chunks moving across the public network remain unreadable to outside observers. Third, it provides peer-to-peer signaling via lightweight WebSocket servers that coordinate handshakes without processing actual file content. Unlike cloud drive platforms that impose strict bandwidth throttling algorithms or storage limits (such as 15 GB account caps), EFShare operates at full available network capacity, constrained only by network hardware throughput and CPU processing power during encryption operations.

How it works

When a transfer initiates, the sending browser splits the source file into uniform binary chunks, typically sized at 16 KB to 64 KB, using the HTML5 File API. The signaling service exchanges Session Description Protocol (SDP) offers and answers along with Interactive Connectivity Establishment (ICE) candidates to discover valid IP address pairs between sender and receiver. Consider a scenario where a user selects a 1.2 GB virtual machine image (`ubuntu_server.iso`). The browser reads the file via `FileReader.readAsArrayBuffer()`, encrypts each 64 KB array buffer sequentially using the Web Crypto API, and pushes the payload through the negotiated `RTCDataChannel`. The receiving browser decodes the incoming array buffers and streams them into local storage via the FileSystem Access API. All core data processing occurs within JavaScript engines such as V8 or SpiderMonkey, using browser-native C++ implementations for cryptographic and WebRTC stack operations. The underlying platform relies on zero third-party software installations, depending exclusively on standard browser APIs including `RTCPeerConnection`, `CryptoSubtle`, and `WebSocket` interfaces. The data flow strictly segregates metadata from content. The external signaling server receives only session identifiers and public ICE candidate parameters (totaling under 5 KB of metadata exchange per session). Actual payload bytes route strictly over encrypted UDP/SCTP tunnels directly between client IP addresses.

How to use it

1. 1Follow these precise instructions to establish a peer-to-peer file session:
2. 21. Open the EFShare web application in a modern WebRTC-compliant web browser.
3. 3Click the 'Select File' button and choose your target file (for example, a 450 MB file named `archive_data.zip`).
4. 4Copy the generated session URL, which contains the room identifier and the private decryption key parameter (e.g., `https://efshare.example/#room=8f31a2&key=e7c9b4`).
5. 5Send the session URL to the designated recipient through your secure messaging channel.
6. 6Instruct the recipient to open the link; verify that both browser tabs remain open and active while the progress indicator moves toward 100%.
7. 7Click 'Save File' on the recipient browser interface once binary assembly finishes to write the decrypted payload to disk.

What it can do

• Utility

Use cases

Assumptions and limitations

Understanding the result

Peer-to-peer secure file sharing. Direct browser-to-browser transfers.

Tool details

More network

References

• /efshare — GitHub Repository

  Upstream project · GitHub

Frequently asked