Social Backup – Data redundancy on trusted machines

Social Backup is my third year project at the University of Cambridge. It provides peer-to-peer backup between trusted peers (you and your friends share storage).

Commercial data storage

Dropbox has revolutionised off-site storage by providing a simple interface to black box data storage. There are a number of inherent disadvantages to using commercial services:

  • Freemium business models may result in data loss and low reliability
  • Companies are at liberty to remove free accounts and increase fees
  • Business catastrophes like liquidation could cause data loss
  • Users have no control over the encryption keys (Amazon S3 servers)

The Internet is becoming distributed

As Internet connectivity improves, the popularity of distributed systems such as BitTorrent (file transfer), and more recently Diaspora (social networking) increase. There is a trend toward ownership of data rather than subscribing to proprietary services, and also peer-to-peer data transmission rather than routing all information through a single point of failure.

Such systems have increased privacy, reliability and failure tolerance, often at the expense of inconsistent state across the distributed system.

My project Social Backup

Social Backup provides each user with data redundancy to restore important information if local failures cause data loss. Redundant data is spread across a set of trusted peers but kept under encryption so that only the original owner can access it. The social aspect promotes fairness and discriminates against free riders: a user who provides 100MB to 10 users will expect a similar allocation from these peers. This user can then use these allocations for repeated storage of small files or for chunking larger articles across the entire space.

My project aims to show that Social Backup is a viable alternative to physical backup and and cloud services.

See also