Of all the online services I use, three deserve kudos for automatically encrypting the data using a decryption key they can never know: CrashPlan, LastPass and Wuala. CrashPlan uses a separate encryption key which can be used instead of your password to encrypt the data before it is sent to their servers.
LastPass and Wuala are using a clever trick. (I can only speculate for Wuala, but given its lack of a separate encryption key seems to indicate they use the same technique.) The user has a user name and password, but to log in the user is sent and the “login key”, which is a hash of “user + password”. That way, the servers never know the password. For encryption the “crypto key” is the hash of “login key + user + password”. Because the server doesn’t know the original password, it is impossible for it to guess the user’s crypto key. That way, the user only has to remember a simple user name and password, and they have full security. Only downside: If you forget your password, you lose all your data. Which is fine, since most password recovery mechanism are flawed (security questions are horrible). (LastPass has a clever way of storing both locally and on the server a per-machine backup password that can be used on local cached data to restore the crypto key, but that’s a different story.)
My point is that there is just no technical reason why an online storage service should have access to all your file unencrypted. It introduces liability for the online storage company, encourages government spying (thus extra costs and hassle for the storage company for all those requests), and could be a major loss of privacy for users. Given the fact that AES is now hardware-accelerated (on most Intel CPUs since 2010), transparent encryption can be easy, fast and secure, so there’s no excuse anymore.
Published on August 21, 2012 at 19:10 EDT
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