Comparison of several commonly used encryption algorithms

Due to the illegal copying of computer software, the leakage of communication and data security are threatened, the problem of decryption and piracy is becoming more and more serious, and even international disputes are caused. Therefore, in information security technology, encryption technology occupies an irreplaceable position, so information encryption technology and encryption The research and development of means has been valued by the computer industry in various countries, and its development is changing with each passing day. Now let's compare several commonly used encryption algorithms.

DES encryption algorithm

The DES encryption algorithm is a block cipher that encrypts data in packets of 64 bits. Its key length is 56 bits, and the same algorithm is used for encryption and decryption. The DES encryption algorithm keeps the key secret and exposes the algorithm, including encryption and decryption algorithms. Thus, only those who have mastered the same key as the sender can interpret the ciphertext data encrypted by the DES encryption algorithm. Therefore, deciphering the DES encryption algorithm is actually the encoding of the search key. For a 56-bit key, if the search is performed by an exhaustive method, the number of operations is 256.

With the continuous development of computer system capabilities, the security of DES is much weaker than it was when it first appeared. However, from the reality of non-critical nature, it can still be considered sufficient. However, DES is now only used for the authentication of legacy systems, and more to choose new encryption standards.

AES encryption algorithm

The AES encryption algorithm is an advanced encryption standard in cryptography. The encryption algorithm uses a symmetric block cipher system. The minimum key length is 128, 192, and 256, and the packet length is 128 bits. The algorithm should be easy to implement in various hardware and software. This encryption algorithm is a block encryption standard adopted by the US federal government. This standard is used to replace the original DES and has been analyzed by many parties and widely used around the world.

The AES encryption algorithm is designed to support 128/192/256 bits (/32=nb) block size (ie packet length); 128/192/256 bits (/32=nk) password length is supported, in decimal Corresponding to 34×1038, 62×1057, 1.1×1077 keys.

RSA encryption algorithm

RSA encryption algorithm is currently the most influential public key encryption algorithm, and is generally considered to be one of the best public key solutions. RSA is the first algorithm that can be used for both encryption and digital signatures. It is resistant to all password attacks known to date and has been recommended by ISO as a public key data encryption standard. The RSA encryption algorithm is based on a very simple number theory fact: it is very easy to multiply two large prime numbers, but at that time, but it is extremely difficult to factorize the product at that time, so the product can be exposed as an encryption. Key.

Base64 encryption algorithm

The Base64 encryption algorithm is one of the most common encoding methods for transmitting 8-bit byte code on the network. Base64 encoding can be used to transfer long identification information in the HTTP environment. For example, in the JAVAPERSISTENCE system HIBEMATE, Base64 is used to encode a long unique identifier into a string that is used as a parameter in HTTP forms and HTTPGETURL. In other applications, it is often necessary to encode binary data into a form suitable for placement in URLs, including hidden form fields. At this time, the use of Base64 encoding is not only short, but also unreadable, that is, the encoded data will not be directly seen by the human eye.

MD5 encryption algorithm

MD5 is a hash function widely used in the field of computer security to provide message integrity protection. A brief description of the MD5 encryption algorithm can be: MD5 processes the input information in 512-bit packets, and each packet is divided into 16 32-bit sub-packets. After a series of processing, the output of the algorithm consists of four 32. The bit grouping consists of cascading the four 32-bit packets to generate a 128-bit hash value.

MD5 is widely used for password authentication and key identification of various software. MD5 uses a hash function, and its typical application is to generate a summary of information for a piece of information to prevent tampering. A typical application of MD5 is to generate a fingerprin fingerprint on a Message to prevent it from being "tampered". If there is a third-party certification body, MD5 can also prevent the "rejection" of the author of the document. This is called the digital signature application. MD5 is also widely used in operating system login authentication, such as UNIX, various BSD system login passwords, digital signatures and many other aspects.

SHA1 encryption algorithm

SHA1 is a message digest algorithm that is as popular as MD5. The SHA encryption algorithm mimics the MD4 encryption algorithm. SHA1 is designed to work with the Digital Signature Algorithm (DSA).

SHA1 is mainly applicable to the digital signature algorithm defined in the digital signature standard. For messages less than 2"64 bits in length, SHA1 will generate a 160-bit message digest. When a message is received, this message digest can be used to verify the integrity of the data. During the transmission, the data is likely to occur. Change, then this will generate a different message digest. SHA1 can not restore information from the message digest, and two different messages will not produce the same message digest. So, SHA1 can verify the integrity of the data, so say SHA1 is a technology for ensuring file integrity.

The SHA1 encryption algorithm can use no more than 264 bits of data input and produce a 160-bit digest. The input is divided into 512-bit blocks and processed separately. A 160-bit buffer is used to hold the middle and final results of the hash function. The buffer can be represented by five 32-bit registers (A, B, C, D, and E). SHA1 is an algorithm that is more secure than MD5. In theory, all digital verification algorithms that adopt the "message digest" method have "collision" - that is, the message digests calculated by two different things are the same, interworking This is the case with cheating. However, it is more difficult for a highly secure algorithm to find the "collision" of the specified data, and it is more difficult to use the formula to calculate the "collision". So far only MD5 has been cracked in the general security algorithm.

Encryption algorithms are the core of cryptography. These encryption algorithms are commonly used encryption algorithms. Some of these algorithms have been deciphered. Some of them are not safe, some are unclear, some are still in step analysis, and some need to be studied in depth. In the mysterious world of encryption algorithms, new members will join and expect safer algorithms to be born.

Small knowledge encryption algorithm:

The basic process of data encryption is to process the original plaintext file or data into an unreadable piece of code, usually called "ciphertext", so that it can only be entered after the corresponding key is entered. The original content is displayed, and the purpose of protecting data from being stolen and read by illegal persons is achieved through such an approach. The inverse of this process is decryption, the process of converting the encoded information into its original data.