Public Vrs. Private

General occasions Private and immortal questions: public or private With this in mind, you are driving to a public school parking lot and watching the same five small cars each day. You and your friend walked to the door and waited for a metal detector. Put the key in the tray and go through the detector to go outside. The two policemen rose to check your backpack. The pocket in the pocket must return to the car and remove it. Return to the metal detector, they will not go out, I thank God.

That is, with public key encryption, users have two keys: a public key and a private key. They can provide public keys to anyone, but they have to keep secret keys secret. That is, the secret key is used to scramble the data, but the data can be decrypted with the public key. The process of scrambling or encrypting data is called a signature. Since this technology is used in a bit coin network, the computer can confirm that the person executing the transaction is the person who is actually talking.

The public key is taken from the secret key. The algorithm used in this process is designed to take several milliseconds to derive the public key from the secret key, but when trying to find the secret key from the public key, it takes longer than existed in the universe takes. That's why you can securely send public keys to people. Finally, you can "sign" the information using the private key in the same way as the public key derivation method. This is a way to prove that you know the secret key. It can be easily checked if someone matches the public key that the message signature claims to be derived from. It is impossible to forge this signature - this is the reason we provide cryptographic security built by the whole Internet!

In a traditional public key cryptosystem, the public key represents an identity. The ownership of the ID is determined by having a secret key that controls the public key. This public / private key model has many useful features that have been used for many years in encrypted identity systems. We do not need much infrastructure to verify the signature - just access the public key. There are several important problems with this traditional model. If you lose your private key (lost, stolen or otherwise) you will lose your identity. In addition, without an additional centralized infrastructure, you can not directly disable keys or safely transfer control of identity to other users. These technical limitations have hampered the adoption of previous attempts to encrypt the identity system.