Altersend

AlterSend is a file transfer application designed to send files directly between devices. It caters to users who need a secure, private, and efficient way to share digital content without relying on intermediary cloud services. The primary purpose is to provide a seamless peer-to-peer (P2P) file sharing experience that bypasses the limitations and privacy concerns associated with traditional cloud storage and transfer methods. The problem AlterSend addresses is the inherent complexity and insecurity of sending large files. Current solutions often involve uploading files to third-party servers, which can lead to data breaches, privacy violations, and frustratingly slow transfer speeds due to size limits and server bottlenecks. This process is not only inefficient but also raises concerns about data ownership and security, especially for sensitive information. AlterSend aims to simplify this by creating a direct, secure channel between users. One of the core features of AlterSend is its peer-to-peer (P2P) architecture. This means files are transferred directly from the sender's device to the recipient's device, eliminating the need for a central server. This direct connection ensures that files never reside on a third-party server, enhancing privacy and security. The P2P nature also contributes to faster transfer speeds, as data travels directly between the two endpoints. Another key capability is end-to-end encryption (E2EE). Every file transfer is secured with strong encryption, meaning only the sender and the intended recipient can access the content. Even if the data passes through a relay server due to network limitations, the content remains unreadable to any intermediary. This robust security measure protects sensitive data from unauthorized access during transit. AlterSend also emphasizes a "no cloud storage, no account, no size limits" policy. Users do not need to create an account to use the service, simplifying the process and enhancing privacy. Furthermore, there are no restrictions on the size of the files that can be transferred, making it suitable for sharing large documents, videos, or software. This approach removes common barriers encountered with other file-sharing services. The application is designed to be cross-platform, supporting both mobile and desktop operating systems. This allows users to send and receive files between different types of devices, such as a smartphone and a laptop, regardless of their operating system. The flexibility of cross-platform compatibility ensures that users can share files from virtually any device they own. AlterSend utilizes a unique connection methodology that combines direct P2P connections with a fallback relay system. When a direct connection is established, files stream directly between devices. If a direct connection is not possible due to network configurations like NAT or CGNAT, the data is routed through a relay server. This relay server, however, only forwards encrypted bytes and cannot access or read the file content, maintaining the end-to-end encryption principle. The discovery and NAT traversal are managed using technologies like Hyperswarm and DHT, with public bootstrap nodes to initiate peer discovery and hole-punching for direct connections. The benefits for users include enhanced privacy and security, as files are not stored on any cloud servers and are end-to-end encrypted. Users also experience faster transfer speeds and the convenience of no file size limits or account registrations. The cross-platform compatibility adds to its utility, allowing for versatile file sharing across different devices and operating systems. Concrete use cases for AlterSend include sharing large video files with collaborators, transferring sensitive documents between personal devices without risk of exposure, or quickly sending design assets between a designer's desktop and mobile device. It's ideal for professionals handling confidential information or individuals who frequently share large media files. AlterSend is an open-source application, licensed under Apache-2.0. It is free to use and available for mobile and desktop platforms. The project is actively developed, with plans to allow users to self-host their own relay servers or offer dedicated relay options for enhanced throughput and bandwidth. The technology stack includes Hyperswarm for discovery and NAT traversal. In summary, AlterSend provides a secure, private, and unlimited file transfer solution by leveraging direct P2P connections and end-to-end encryption, eliminating the need for cloud storage and user accounts.