*藏色散人**Original**2020-12-24 10:18:40**63030browse*

Recovery key refers to Key recovery, which is a private key encryption method. The authorized party can use special software to recover the key from the encrypted data; that is to say, this method can recover from the encrypted data. keys, and any encryption software must implement key recovery.

#The operating environment of this article: windows10 system, thinkpad t480 computer.

Key recovery, a method of private key encryption in which an authorized party (such as a government agency) uses specialized software to recover the key from encrypted data.

Key recovery Key recovery

A private key encryption method. Authorized parties, such as government agencies, can recover keys from encrypted data using specialized software. By law, any encryption software exported from the United States after 1998 must enable key recovery. This provision replaces an earlier requirement that any exported encryption software must implement key escrow.

Purpose: Keys can be recovered from encrypted data

Legal regulations: Any encryption software must implement key recovery

Related extensions:

Encryption Keys are divided into two types: symmetric keys and asymmetric keys

Both types of keys

According to whether the encryption key and decryption key used in the cryptographic algorithm are the same and whether they can be encrypted The decryption process is derived from the process (or the encryption process is derived from the decryption process). Cryptosystems can be divided into symmetric cryptography (also called single-key cryptography, secret key cryptography, symmetric key cryptography) and asymmetric cryptography. System (also called dual-key cryptography, public key cryptography, asymmetric key cryptography).

Symmetric key encryption, also known as private key encryption or session key encryption algorithm, means that the sender and receiver of information use the same key to encrypt and decrypt data. Its biggest advantage is that it has fast encryption/decryption speed and is suitable for encrypting large amounts of data, but key management is difficult.

Asymmetric key encryption system, also known as public key encryption. It requires the use of different keys to complete encryption and decryption operations respectively. One is published publicly, that is, the public key, and the other is kept secretly by the user, that is, the private key. The sender of information uses the public key to encrypt, and the receiver of the information uses the private key to decrypt. Public key mechanisms are flexible, but encryption and decryption are much slower than symmetric key encryption.

So in practical applications, people usually use the two together. For example, the symmetric key encryption system is used to store large amounts of data information, while the public key encryption system is used to encrypt keys.

For ordinary symmetric cryptography, the same key is used for encryption operations and decryption operations. Usually, the symmetric encryption algorithm used is relatively simple and efficient, the key is short, and it is extremely difficult to decipher. Since the confidentiality of the system mainly depends on the security of the key, it is important to safely transmit and store the key on an open computer network. Serious problem. Precisely because both parties use the same key in symmetric cryptography, functions such as data signature and non-repudiation cannot be achieved.

Since the 1970s, some scholars have proposed a public key system, which uses the mathematical principle of one-way functions to achieve the separation of encryption and decryption keys. The encryption key is public and the decryption key is secret. This new cryptographic system has attracted widespread attention and discussion in the cryptography community.

Unlike ordinary symmetric cryptography that uses the same key to encrypt and decrypt data, asymmetric key encryption technology uses a pair of matching keys to encrypt and decrypt. It has two keys, one is The public key is a private key, and they have this property: each key performs a one-way processing of data, and the function of each key is exactly the opposite of the other. When one is used for encryption, the other for decryption. Files encrypted with the public key can only be decrypted with the private key, and files encrypted with the private key can only be decrypted with the public key. The public key is made public by its owner, while the private key must be kept secret. To send a confidential message, the sender must encrypt the data using the recipient's public key. Once encrypted, it can only be decrypted by the recipient using his or her private key. Conversely, users can also process data using their own private keys. In other words, the key pair can work in any direction. This provides the basis for "digital signature". If a user uses his own private key to process the data, others can use the public key he provided to process the data. Since only the owner knows the private key, the processed message forms an electronic signature—a document that no one else can produce. The digital certificate contains public key information, thereby confirming the identity of the user who owns the key pair.

A simple public key example can be represented by a prime number. The algorithm for multiplying prime numbers is used as the public key. The algorithm for decomposing the resulting multiplication into the original prime numbers is the private key. Encryption is to transfer the information you want to transmit. Add prime numbers when encoding, and send it to the recipient after encoding. After anyone receives this message, if he does not have the private key owned by the recipient, the decryption process (actually the process of finding prime numbers) will result in the problem of finding the prime number. The process of prime numbers (factoring prime numbers) takes too long to decipher the information.

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