How HTTPS secures connections

Why does data need to be encrypted when transmitted over the network? http:
//dev.yesky.com/384/35303884.shtml

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Asymmetric encryption

As shown in the figure below, between A and B The secure transmission of important information is accomplished using asymmetric encryption.
Schematic diagram of the working process of
asymmetric of the working process of asymmetric encryption
1. Party B generates a pair of keys (public key and private key) and discloses the public key to other parties.
2. Party A who has obtained the public key uses the key to encrypt the confidential information before sending it to Party B.
3. Party B decrypts the encrypted information with another private key (private key) kept by itself. Party B can only use its private key (private key) to decrypt the information encrypted by the corresponding public key.
During the transmission process, even if the attacker intercepts the transmitted ciphertext and obtains B's public key, he cannot crack the ciphertext, because only B's private key can decrypt the ciphertext.
Similarly, if B wants to reply the encrypted information to A, then A needs to first publish A's public key to B for encryption, and A saves A's private key for decryption.


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Symmetric encryption VS asymmetric encryption
http://www.cnblogs.com/jfzhu/p/4020928.html

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Website https, user's own public key and private key~
http://www.2cto.com/Article/201407/315433.html