What Is Asymmetric Cryptography?

The symmetric encryption algorithm uses the same key when encrypting and decrypting; the asymmetric encryption algorithm requires two keys for encryption and decryption. These two keys are the public key (public key) and Private key (private key).

American Scholar, 1976

Encryption technology is generally divided into two types: symmetric encryption and asymmetric encryption. The more widely used is symmetric encryption, the main feature is that the same key is used for encryption and decryption. Asymmetric encryption uses two keys for encryption. Different keys are used during encryption and decryption. These two keys are "public key" and "private key". I want to be able to work normally. Completion of the encryption and decryption process requires pairing. In the process of use, the "public key" is public, and the "private key" must be kept secret by the sender, and only owned by the holder. If the symmetric encryption method is used to transmit encrypted files over the network, no matter what method is used to tell the key to the other party, they may be eavesdropped. The asymmetric encryption method has certain advantages because it contains two Key, and only the "public key" in it can be made public. The receiver only needs to use the private key that he already owns to decrypt, so that the security generated by the key during transmission can be well avoided. problem. ^[2]

1. Party B generates a pair of keys (public and private keys) and publishes the public key to other parties.

2. Party A who has obtained the public key uses the key to encrypt confidential information before sending it to Party B.

3. Party B then decrypts the encrypted information with another private key (private key) that it holds. 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, the ciphertext cannot be cracked because only the private key of B can decrypt the ciphertext.

Similarly, if B wants to reply to the encrypted information, then A needs to publish A's public key to B for encryption, and A keeps A's private key for decryption.

The asymmetric encryption algorithm needs to have both a public key and a private key when it is used. The public key corresponds to the private key.

The encryption key (public key) and decryption key (secret key) used in the public key cryptosystem are different. Because the encryption key is public, the distribution and management of the key is simple, and digital signatures can be easily implemented, so it is most suitable for the needs of e-commerce applications. Its main advantages are:

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First, the use of asymmetric algorithms in mobile phone SMS transmission

Sending and receiving text messages on mobile phones has become an important channel for people's daily communication. The short message service has gradually entered the people's life from the mobile terminal. With the deepening of the important mobile SMS application business fields such as securities trading, more traditional text messages have begun to use text plus The way of information dissemination, the traditional business channels that use short message information for dissemination have been unable to meet people's needs, which puts more requirements on the security application of short messages. In order to ensure the security of mobile phone short message transmission information, the security of mobile phone short messages can be encrypted in various ways. For example, RSA algorithm can be used to encrypt the password, and modern technology can be used to encrypt the password information to improve the security of the short message. When using RSA technology, a pair of secret keys can be generated first, and then the security of the secret key is processed at the receiving end of the mobile phone and the receiving end of the information. If the sending end of the mobile phone receives the ciphertext, the mobile phone that sends the information sends out It should be in plain text. If the receiving end of the receiving message receives the encrypted information sent out, then the mobile phone receiving the information receives the plain text message sent by the sending end. Before the mobile phone sends a signal, the user needs to edit the text of the text message. In order to realize the secure transmission of the information, the text message needs to be encrypted, and the public key and the private key must be published together. The RSA algorithm performs calculations, so the ciphertext can be easily reduced to plaintext. After receiving the plain text message, the user receiving the gateway will transmit the content of the short message between the address information according to the pre-stored address of the operator. During the signal transmission, the router can send the short message to the target path, and then follow the information source. The ciphertext of the short message is saved and decrypted at the address, and it is finally restored to the plaintext information retained at the source address, so the security of the information transmission is strengthened.

Second, the use of asymmetric algorithms in video conferences

After the development of modern technology, video conferences have become more and more. If a lot of information is leaked out through signal transmission, it will cause security problems. Video conferences are generally conducted between companies and companies or between companies and companies. Important communication channels for communication may involve trade secrets. Therefore, if an irrelevant person learns the relevant information or destroys it, it will lead to the duplication and destruction of the data, which will lead to the loss. At the same time, the video conference generally occurs in the company. In the meantime, if the video conference also involves state organs, the leakage of state secrets may also cause foreign countries to obtain China's military intelligence, so the security issue of video conferences is particularly important. The encryption method of modern cryptography can be used to encrypt the conference content, and the encrypted mixed application of algorithm can be realized by using RSA algorithm or DES algorithm, and the application of video conference system can be realized. These encryption algorithms are applied in video conferences. Combining encryption technology and secret key technology for public key distribution and distributed key transmission will enable the secret key to be used in symmetric algorithms and use appropriate symmetric algorithms for conference communications. The content is encrypted to realize multi-unit control of video information transmission. ^[4]