Quote Originally Posted by Oddwaffle View Post
On the other hand, I have opened a similar token before and it's possible to replace the battery. You might have to reset it and sync it again with SE (like syncing a watch with your current time).
Square Enix and Blizzard use VASCO Digipass GO 6 tokens. It is not possible to replace the battery in these, it will suicide if you tamper with it. Also the key is kept in volatile RAM and when the battery runs down to a certain % it is lost (I'm not sure if it just runs down and is lost or if the token suicides itself when it determines the battery has lost too much power for it to run reliably anymore, probably the latter)

It is in theory possible to extract the key from one of these tokens but it requires equipment and facilities only available to large corporations and governments, and because each token has a unique key you would be spending millions to break one person's account and one person's only. So it's completely not worth it. They have designed these things to be very physically tamper resistant.