SpiderOak Secure Cloud Storage
SpiderOak is one of many cloud storage vendors to choose from. Vendors usually provide several gigabytes (GB) of free cloud storage, with an option to buy more storage. However, users must be careful to read the specifications and terms of service to determine if the stored files are secure and encrypted.
I have compared many cloud storage vendors including Google Drive, Dropbox, SugarSync, Mozy, Carbonite, justcloud, OneDrive, and livedrive. Many of these storage providers might work for casual storage of music, videos, photos, and non-confidential information.
Encryption versus Plain Text Cloud Storage
When storing confidential information, users must understand the use of encryption. Some vendors only provide encryption while the data is in transit from your device to the cloud storage. This protects against eavesdropping and data modification along the way.
But, many vendors then decrypt the data once it arrives at the cloud storage and store the data in plain text. That means that someone could break in to the cloud storage and read the data. That is not acceptable for secure storage.
Some vendors encrypt the data while it is in transit to the cloud, and then store the data in encrypted form. This is more secure, but there is still a potential security problem. If the cloud storage vendor knows the encryption key, which many of them do, then they could use the encryption key to decrypt the data and read it. This is not acceptable for secure storage.
Private Encryption Key
SpiderOak uses Zero-Knowledge privacy protection. The data is encrypted on your device before it is sent over the internet (Pre-Internet Encryption) and then stored in encrypted form in the cloud storage. You generate and keep the encryption key and do not provide it to SpiderOak. So, the data is secure, only you have the encryption key.
You must keep the encryption key secure and must not lose it. Since SpiderOak does not have the key, if you lose it, you will not be able to access the data stored in the cloud. You should have a strong key, kept in a secure location, such as a password manager like KeePass. You should also keep a copy of the encryption key in a backup location, such as a fireproof safe.
I found that the combination of end to end encryption, encrypted storage, and Zero-Knowledge privacy protection to be the best security available for personal or business use. When doing an initial backup of files from my computer to SpiderOak, the data transfer speed was about 400 MB/hour. That is slower than some other cloud storage providers, but I have not found that to be a problem, once the initial backup was complete.
Once the files are backed up to the cloud, you can synchronize several devices to keep the files up to date and accessible from home, work or on the road, while using a desktop or notebook PC, tablet PC or smartphone. You can also share files with others for collaboration
Redundant Local Backup
For redundant backup, you should also keep another local backup of your data files. I use a microSDHC flash memory card which is compact, rugged and operates in a wide range of temperatures. One copy can be kept in a fireproof safe, while another copy can remain in your computer, set up for daily backups.
Update: July 23, 2015, SpiderOakONE version 6.0 released with new pricing plans
SpiderOakONE now offers a 2 GB free trial for 60 days. Pricing plan choices include $7/month or $79/year for 30 GB, $12/month or $129/year for 1 TB, and $25/month or $279/year for 5 TB.