Quantum cryptography doesn't rely on the difficulty of mathematical problems, but on the fundamental laws of physics.

要真正伟大，必须与人民站在一起，而不是凌驾于他们之上。

领导就是服务，而不是被服务。

The meaning of life differs from man to man, from day to day and from hour to hour.

Society can and does execute its own mandates， and if it issues wrong mandates instead of right， or any mandates at all in things with which it ought not to meddle， it practices a social tyranny more formidable than many kinds of political oppression， since， though not usually upheld by such extreme penalties， it leaves fewer means of escape， penetrating much more deeply into the details of life， and enslaving the soul itself.

There is no such thing as great wisdom in the world, just as there is no such thing as talent. What exists is triviality. If you keep doing repetitive things, you become an expert; if you do repetitive things with special focus, you become a master.