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This article mainly explains "what is the core encryption technology of block chain". Interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Next, let the editor take you to learn "what is the core encryption technology of the block chain"?

Digital encryption technology is the key to the application and development of block chain technology. Once the encryption method is cracked, the data security of the block chain will be challenged, and the unusurable modification of the block chain will no longer exist. Encryption algorithms are divided into symmetric encryption algorithms and asymmetric encryption algorithms, and asymmetric encryption algorithms are mainly used in block chain. according to the problems on which asymmetric encryption algorithms are based, public key cryptosystems are generally divided into three categories: large integer decomposition problems, discrete logarithm problems and elliptic curves.

Encryption algorithms are generally divided into symmetric encryption and asymmetric encryption. Asymmetric encryption refers to the encryption technology integrated into the block chain to meet the security requirements and ownership verification requirements. Asymmetric encryption usually uses two asymmetric passwords, called public key and private key, in the process of encryption and decryption.

The asymmetric key pair has two characteristics: first, after encrypting the information with one of the keys (public key or private key), only the other corresponding key can be unlocked. Second, the public key can be made public to others, while the private key is kept secret, and others cannot calculate the corresponding private key through the public key.

Asymmetric encryption is generally divided into three main categories: large integer decomposition problem class, discrete logarithm problem class, elliptic curve class. The class of large integer decomposition problem refers to using the product of two larger prime numbers as the encryption number. Because the emergence of prime numbers is irregular, the solution can only be solved through continuous trial calculation. The class of discrete logarithm problem refers to an asymmetric distributed encryption algorithm based on the unsolvability of discrete logarithm and strong one-way hash function. The elliptic curve class refers to the use of planar elliptic curves to calculate groups of asymmetric special values, and Bitcoin uses this kind of encryption algorithm.

The application scenarios of asymmetric encryption technology in block chain mainly include information encryption, digital signature and login authentication.

(1) in the information encryption scenario, the sender (marked as A) uses the public key of the receiver (marked as B) to encrypt the information and then sends it to BMageB to decrypt the information using his own private key. The encryption of bitcoin transactions belongs to this scenario.

(2) in the digital signature scenario, sender A uses its own private key to encrypt the information and then sends it to BMagazine B. it uses A's public key to decrypt the information, so as to ensure that the information is sent by A.

(3) in the login authentication scenario, the client encrypts the login information with the private key and sends it to the server, and the latter uses the client's public key to decrypt and authenticate the login information.

Note the differences in encryption in the above three scenarios:

Information encryption is public key encryption, private key decryption to ensure the security of information; digital signature is private key encryption public key decryption to ensure the attribute of digital signature; login authentication private key encryption, public key decryption.

Take the Bitcoin system as an example, its asymmetric encryption mechanism is shown in figure 1: Bitcoin systems generally generate 256-bit random numbers as private keys by calling the random number generator at the bottom of the operating system. The total amount of Bitcoin private keys is so large that it is extremely difficult to obtain the private keys containing Bitcoin by traversing all the private key spaces, so cryptography is secure. For easy identification, the bitcoin private key in 256-bit binary form will be converted by SHA256 hash algorithm and Base58 to form a 50-character length easy to identify and write private key to provide to the user. The public key of Bitcoin is a random number with a length of 65 bytes first generated by the private key through the Secp256k1 elliptic curve algorithm. The public key can be used to generate the address used in bitcoin transactions. The generation process is that the public key is first hashed by SHA256 and RIPEMD160 to generate a summary result of 20 bytes (that is, the result of Hash260), and then transformed into a bitcoin address of 33 characters by SHA256 hashing algorithm and Base58 conversion.

The process of public key generation is irreversible, that is, the private key cannot be derived from the public key. The public and private keys of Bitcoin are usually stored in the Bitcoin wallet file, of which the private key is the most important. Losing the private key means losing all bitcoin assets at the corresponding address. In the existing Bitcoin and blockchain systems, according to the actual application requirements, multi-private key encryption technology has been derived to meet more flexible and complex scenarios such as multi-signature.

At this point, I believe you have a deeper understanding of "what is the core encryption technology of the block chain". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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