Hi, I've created an Opera account to sync across OS X and two Android devices. On OS X, I chose to encrypt all synchronized data with a master passphrase. But I can't tell the passphrase to Opera on Android. That's not discussed by instructions on http://www.opera.com/help/account, and I found no way by playing around in the interface or searching these forums.
For now, I'm resetting synchronization and disabling it for passwords—encrypting passwords only by a password that Opera has is not robust enough—even if I trust Opera's honesty, that's no guarantee if Opera's DB is hacked.