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. Its first offering, its online backup service later branded "SpiderOak ONE", launched in December 2007. 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 differentiates itself from its competition by this kind 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; in 2009, the company announced its intent for the SpiderOak One client's code to be fully open-source in the future. As of 2016[update], the SpiderOak One client's source code is only available open-source for mobile platforms, with no current plans to make the desktop client's code open-source. SpiderOak's password manager Encryptr is open-source; the source code for its group messaging application Semaphor is published to allow auditing.
As of 2014, SpiderOak was headquartered in Chicago and employed 42 staff, headed by CEO Alan Fairless. Around the same time, the company had offices in Chicago and Kansas City, and was hiring remote employees inside and outside of the US. In 2015, SpiderOak raised $3.5 million in Series A funding, bringing its total funding to around $9 milion.
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.
In November 2017, founder Alan Fairless was replaced as CEO by Christopher Skinner, who announced that the company would be expanding into enterprise software, partially funded by a $2 million Series B round.
On August 1, 2018, the warrant canary on SpiderOak's 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 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.
- "SpiderOak Review: Cloud Storage reviews at". Nextadvisor.com. Archived from the original on 2013-01-24. Retrieved 2013-08-10.
- "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.
- "SpiderOak/Encryptr". GitHub. Retrieved 2017-04-24.
- "Semaphor Verifiable Source". spideroak.com. Retrieved 2017-04-24.
- "About SpiderOak". Archived from the original on 2014-10-09.
- "About Crypton".
- Klint Finley (March 1, 2013). "Open Source Project Prepackages Kim Dotcom's Security". Wired.
- Yadron, Danny; MacMillan, Douglas (2014-07-14). "Snowden Says Drop Dropbox, Use SpiderOak". WSJ.com Digits. The Wall Street Journal. Retrieved 1 September 2014.
- "SpiderOak Grows Enterprise Revenue 300%, Doubles Headcount". spideroak.com. SpiderOak. December 10, 2013. Archived from the original on August 30, 2014.
- "Chris Cooley shares how SpiderOak's distributed team works". Silicon Prairie News. August 29, 2014.
- Elahi, Amina (2015-07-23). "SpiderOak raises $3.5 million to store data with 'zero knowledge'". chicagotribune.com. Retrieved 2019-10-07.
- "Why we will no longer use the phrase Zero Knowledge to describe our software". spideroak.com. SpiderOak. February 8, 2017. Retrieved February 13, 2017.
- Kaberline, Brian (2017-11-15). "SpiderOak introduces changes in top post, target customers". Kansas City Business Journal. Retrieved 2019-10-07.
- "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.
- "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.
- "Spideroak: Free Online Backup, File and Folder Sync, Share & Storage for Windows, Mac, and Linux – SpiderOak.com". SpiderOak. Retrieved 2009-11-04.