Tarsnap - Online backup for the truly paranoid

Tarsnap is a secure, efficient online backup service:

• Encrypted: Your data is only accessible with your personal key.

We can't access your data even if we wanted to!

• Source code: Client code is available.

You don't have to trust us; you can check the encryption yourself!

• Deduplication: Only unique data between the current file and the encrypted archive is uploaded.

This reduces the bandwidth and storage required, saving you money!

Tarsnap runs on UNIX-like operating systems (BSD, Linux, macOS, Cygwin, etc.).

Work on Tarsnap began in September 2006, when the author, Dr. Colin Percival, decided that he wanted a better online backup service than what was available at the time. After more than two years of development and internal testing, Tarsnap officially entered public beta in November 2008 and became profitable in February 2009. In September 2011, Tarsnap Backup Inc. was incorporated in British Columbia, Canada.

The Tarsnap client code is built around the open source libarchive archive processing library. Although the Tarsnap code is not distributed under an open source license, Tarsnap gives back to the open source community through bug fixes and libarchive enhancements (40 commits and counting) and by releasing brand new code when possible (such as scrypt key derivation functions and file encryption code).

Currently, the Tarsnap service is provided using the infrastructure of Amazon Web Services.

About the Author

Dr. Colin Percival entered Simon Fraser University to study mathematics at the age of 13, and then studied for a PhD in computer science at Oxford University. His thesis covered problems in string matching, data compression, and file synchronization.

In January 2004, Colin became a FreeBSD committer and member of the FreeBSD Security Team; he became FreeBSD Security Officer in August 2005, a position he held until May 2012. In addition to his role as FreeBSD Security Officer, he is probably best known in the FreeBSD community for his work on FreeBSD Update and Portsnap.

In addition to working directly on security issues through his experience as FreeBSD Security Officer, Dr. Percival has published several research papers in areas ranging from numerical analysis to cryptography, including the first published cryptographic attack on shared caches in Intel's "Hyper-Threaded" processors.