It was about a year ago that I found out about Dropbox, and immediately downloaded it and started using it. Because it was the first one I ran into, I briefly assumed they were the first one to do cross-computer file syncing. But it turned out that SugarSync for one had been around longer, had more features, and offered more free storage. I still use Dropbox because it's integrated with so many other applications, and because so many people are familiar with it and use it as their main file sync/sharing service.
A few months ago I switched to using SugarSync as my primary service, purchasing the discounted year's subscription. I chose them for three main reasons. 1) I can choose which folders will sync and which won't (as compared to having only one Dropbox folder) 2) They offer the widest variety of platform apps, including Linux, Blackberry, and even Windows Phone. 3) It's possible to securely share files with password protected links, and it's possible to layer additional security onto their platform. But with new offerings on the market, I'm wondering whether I'll stick with them long term. The Verge recently did a pretty good comparison for the main players in the sync market - check it out here.
The new one that has caught my interest is called Spideroak. "Huh, strange name." Then I looked at what they're doing. They're applying a high-security model of access and encryption that's known as TNO or Trust No One. This is the level of security required by HIPPA regulations when anything is handled by a third party. It basically means, "I'm the only one who has the keys to my locked files, and I'm not going to share them with anyone." In this model, everything is encrypted before it leaves your computer so that you are the only one who can unlock and read the contents. It's then sent over a secure SSL encrypted internet connection, stored on remote servers, and synced to your other devices. When on their servers, they have zero access to the file contents, because they were locked before you sent them and Spideroak doesn't have the keys. Dropbox and SugarSync on the other hand, transmit and store your files encrypted, but they also have the keys to unlock them. Spideroak has structured things so they never have the key to unlock your files, only you do.
To date, I've offered an additional level of security on top of other sync services using TruCrypt, a free open source encryption app. This allows me to do the same thing Spideroak is doing - encrypt and lock files before they are sent to the cloud. But it takes an extra couple of steps each time, and took some time to set up. So now I'm seriously looking at Spideroak because they have integrated it into their sync solution. Less work for me, same level of security. I'm liking that.