SpiderOak Semaphor 1.1.0 Mac OS X
|Initial release||December 2007|
7.5.0 / February 14, 2019
|Operating system||Windows, macOS, Debian, Fedora, Slackware, Android, iOS|
|Type||Online backup service and collaboration tool|
|License||Proprietary (GPLv3 for some tools)|
SpiderOak is a US-based collaboration tool, online backup and file hosting service that allows users to access, synchronize and share data using a cloud-based server, offered by a company of the same name. SpiderOak is accessible through an app for Windows, Mac and Linux computer platforms, and Android, N900 Maemo and iOS mobile platforms.
According to SpiderOak, the software uses encrypted cloud storage and client-side encryption key creation, so SpiderOak employees cannot access users' information. SpiderOak distinguishes itself from its competition in provision of encryption, in provision for syncing files and folders across multiple devices, and in automatic de-duplication of data.
Some components of SpiderOak are open-source, and as early as 2009 the company announced their intent for the client to be fully open-source in the future. As of 2016[update], SpiderOak ONE's source code is only available for mobile platforms, with no current plans to open source the desktop client. SpiderOak's password manager Encryptr is open source; the source code for its group messaging application Semaphor is published to allow auditing.
SpiderOak is headquartered in Chicago and in 2014 employed 42 staff, headed by CEO Alan Fairless. SpiderOak has offices in Chicago and Kansas City, and hires remote employees inside and outside of the US.
In February 2017, SpiderOak discontinued using the phrase "zero knowledge" to describe their service following public criticism that the phrase conflicted with the mechanism behind cryptographic zero-knowledge proofs. SpiderOak adopted the phrase "no knowledge" for their marketing.
On August 1, 2018, the warrant canary on their website briefly vanished, followed by some system downtime. It was then replaced by a transparency report. Five days later, the canary was re-signed using GPG encryption. By August 9, Spideroak had also updated their transparency report, making a statement concerning the canary. It is impossible to tell if the change was internally driven or canary was tripped and the company has been compelled by court order to hide the fact. 
- All data accessible in one de-duplicated location
- Configurable multi-platform synchronization
- Preserve all historical versions and deleted files
- Share folders in web ShareRooms with RSS notifications
- Retrieve files from any internet-connected device
- Claimed "no knowledge" data encryption if you only use the desktop client, that is, no sharing, web-access, or mobile access. This claim, however, cannot be confirmed due to the client being closed source
- Unlimited devices
- A layered approach to encryption, using a combination of 2048-bit RSA and 256-bit AES
- Comparison of file hosting services
- Comparison of file synchronization software
- Comparison of online backup services
- File synchronization
- "SpiderOak Service Agreement". SpiderOak. Retrieved June 9, 2013.
- "Spideroak Service Description". SpiderOak. Archived from the original on January 3, 2010. Retrieved June 19, 2009. Cite uses deprecated parameter
- "SpiderOak Review: Cloud Storage reviews at". Nextadvisor.com. Archived from the original on 2013-01-24. Retrieved 2013-08-10. Cite uses deprecated parameter
- "SpiderOak: Dropbox for the security obsessive".
The chief difference between SpiderOak and its competitors for the security and privacy-conscious is in how the services treat user data.
- Carla Schroder (2009-01-22). "Spideroak: Secure Offsite Backups for Linux". LinuxPlanet. Retrieved 2009-02-26.
- "Spideroak: Engineering Matters". SpiderOak. Retrieved 2009-11-04.
- "Why isn't SpiderOak open source yet? When will it be?". Archived from the original on 2016-10-05. Retrieved 2016-10-05. Cite uses deprecated parameter
- "SpiderOak/Encryptr". GitHub. Retrieved 2017-04-24.
- "Semaphor Verifiable Source". spideroak.com. Retrieved 2017-04-24.
- Yadron, Danny; MacMillan, Douglas (2014-07-14). "Snowden Says Drop Dropbox, Use SpiderOak". WSJ.com Digits. The Wall Street Journal. Retrieved 1 September 2014.
- "About SpiderOak". Archived from the original on 2014-10-09. Cite uses deprecated parameter
- "About Crypton".
- Klint Finley (March 1, 2013). "Open Source Project Prepackages Kim Dotcom's Security". Wired.
- "SpiderOak Grows Enterprise Revenue 300%, Doubles Headcount". spideroak.com. SpiderOak. December 10, 2013. Archived from the original on August 30, 2014. Cite uses deprecated parameter
- "Chris Cooley shares how SpiderOak's distributed team works". Silicon Prairie News. August 29, 2014.
- "Why we will no longer use the phrase Zero Knowledge to describe our software". spideroak.com. SpiderOak. February 8, 2017. Retrieved February 13, 2017.
- "A Transparency Report is a Canary". SpiderOak.com. 2018-08-06. Retrieved 2018-08-10.
- "Transparency report". SpiderOak.com. 2018-08-03. Retrieved 2018-08-10.
- Schneier, Bruce. "SpiderOak's Warrant Canary Died". Schneier on Security. Retrieved 15 August 2018.
- "How do I use the SpiderOak Web API?". SpiderOak FAQs. Archived from the original on 22 August 2014. Retrieved 21 August 2014. Cite uses deprecated parameter
- "SpiderOak to Become OSS & More: What to Expect From Us in 2014 (PART I)". The Spideroak Blog. Archived from the original on 22 August 2014. Retrieved 21 August 2014. Cite uses deprecated parameter
- "Spideroak: Free Online Backup, File and Folder Sync, Share & Storage for Windows, Mac, and Linux – SpiderOak.com". SpiderOak. Retrieved 2009-11-04.