You only need to remember your password, from which your key is derived. You also need to write a recovery string (which can be used to derive your key as well)

You only need to remember your password, from which your key is derived. You also need to write a recovery string (which can be used to derive your key as well) on a piece of paper and store it somewhere safe as a backup in case you forgot your password. Now from our side, there's very little chance we lose your key (we do encrypted offsite backups every hour) and even then we're currently implementing "presigned transactions" that use "nLockTime" function in Bitcoin protocol to let you claim your Bitcoins after certain amount of time in case we disappear. Also, we require you to use 2-factor, so even if your computer gets hacked, attacker still can't emulate your actions to steal your coins. And if an attacker hacks our server, he only gets one key of two needed to spend the funds.