One of the most difficult thing about computer security is authentication: how do I know that you are who you say you are? Regardless how good security technology gets, the problem always comes down to the ultimate fact that we are dealing with humans. Computers execute programs, commands, and protocols perfectly; it's easy to authenticate computers. But their human operators can easily be duplicitous.
To communicate face-to-face is easy: you know who you're talking to, and there is only one person to trust. As soon as a mediator is involved, whether it's a classmate passing along a note, a chat server owned by a profit-making corporation sending and storing messages, or a corporation facilitating a trade of valuable assets, a network of trust is implied, and this makes things very, very complicated. Bitcoin enabled secure, direct party-to-party exchanges of money without the mediation of financial institutions or government-controlled currency, but it did not even attempt to solve the very difficult problems of authentication and trust.
One of the most difficult thing about computer security is authentication: how do I know that you are who you say you are? Regardless how good security technology gets, the problem always comes down to the ultimate fact that we are dealing with humans. Computers execute programs, commands, and protocols perfectly; it's easy to authenticate computers. But their human operators can easily be duplicitous.
To communicate face-to-face is easy: you know who you're talking to, and there is only one person to trust. As soon as a mediator is involved, whether it's a classmate passing along a note, a chat server owned by a profit-making corporation sending and storing messages, or a corporation facilitating a trade of valuable assets, a network of trust is implied, and this makes things very, very complicated. Bitcoin enabled secure, direct party-to-party exchanges of money without the mediation of financial institutions or government-controlled currency, but it did not even attempt to solve the very difficult problems of authentication and trust.