2.4.1 RSA Public Key Encryption Video
The RSA crypto systems is one of the lovely and really important applications of number theory in computer science. So let's start talking about it. The RSA crypto system is what is known as a public key cryptosystem, which has the following really amazing properties-- namely, anyone can send a secret encrypted message to a designated receiver. This is without there being any prior contact using only publicly available information. Now, if you think about that, it's really terrific because it means that you can send a secret message to Amazon that nobody but Amazon can read even though the entire world knows what you know and can see what you sent to Amazon. And Amazon knows that it's the only one can decrypt the message you sent. This in fact is hard to believe if you think about it. It sounds paradoxical. How can secrecy be possible using only public info? And in fact, the existence of this public key cryptosystem has some genuinely paradoxical consequence, ...