You would be right -- if the use case for this was transmitting encrypted information. The reason I made this was mostly for email. Sometimes I want to send someone a message and not have it exist forever. In that case, you could send a link to the message along with the key. Then, after n hours, the message would cease to exist anywhere (assuming the server fulfills its contract). This works better than having the server just store the whole message, since now the server gets to be ignorant of the message's content. Mostly this was a fun little project I wanted to share :)