In addition to Weibo, there is also WeChat
Please pay attention
WeChat public account
Shulou
2025-01-23 Update From: SLTechnology News&Howtos shulou NAV: SLTechnology News&Howtos > IT Information >
Share
Shulou(Shulou.com)11/24 Report--
I believe that fans, like Mr. Archive, have seen these news more or less:
A large amount of personal information of a bank is sold.
A telecom operator caused service interruption due to a network attack.
International port giant attacked by blackmail virus
.
In recent years, information leakage, network attacks and other security incidents emerge one after another. The security of Internet communication is becoming more and more important. As one of the important methods to maintain information security, password has become an indispensable part of network communication. However, did you know that the history of passwords can be traced back to the 5th century BC? Today, let's unravel its mysterious and charming veil.
The development of cryptography can be divided into three stages: classical cryptography, modern cryptography and modern cryptography. Cryptography has undergone many changes from an art to a science.
01. Classical cryptography began to originate and develop gradually during a long period before the end of the 9th century. At this stage, cryptography is spread as an art. People use paper, pen or simple instruments to replace and replace the content by hand.
I wonder if everyone has ever written a Tibetan poem to his or her beloved. In fact, in that ignorant time, we inadvertently completed a "encryption" operation of the information. In ancient times, Tibetan head poems, "steganography", and the "Da Vinci cipher barrel" which can be opened by turning to the correct position of the turntable abroad, all achieved the effect of encryption through the concealment of the message itself or the concealment of the specific content. later, with the continuous improvement of awareness and thinking, smart people began to change the way to achieve the "encryption" of information.
Typical passwords: Caesar password, Virginia password
Caesar cipher is one of the simplest and best known encryption techniques. All the letters on the message are "encrypted" by offsetting a fixed number (that is, offset n) backward (or forward) on the following single alphabet. Similarly, using the offset as a decryption key, we can decrypt the ciphertext.
The Virginia password is an encryption algorithm that uses a series of Caesar passwords to form the alphabet of passwords, that is, to encrypt the same message in the form of multiple alphabets. Each message corresponds to the column sequence number, and the filled key is used as the row sequence number to locate the encrypted characters at the intersection of the rows and rows in the table, thus increasing the difficulty of cracking the password.
02. Modern cryptography from the early 20th century to the late 1940s or so in the 1950s
The first leap in cryptography: Shannon published Communication Theory of Secrecy System (Communication Theory of secure Systems). The article established the basis of information theory (communication professionals are all familiar with him), and put forward two design principles of password confusion and diffusion. Cryptography began to step into the track of science. In the later stage, people use manual or electric machinery to achieve complex substitution and replacement.
I believe you have seen a lot of spy movies, and many classic spy movies will also involve password ideas. In those war years, cryptography played a key role, and it could even determine the final outcome of the war. Among them, the most typical is the British deciphering the German Enigma encryption machine during World War II. Because the Enigma encryption machine makes full use of the design principles of confusion and diffusion, and the key used is updated every day, it is difficult to crack the Enigma encryption machine only by relying on the manpower at that time. Finally, Alan Turing (worship) participated in the deciphering work-by studying the construction of the Enigma machine, we successfully built an Enigma machine for inverse transformation to decipher the Enigma encryption machine, which also played a key role in the final victory of the war.
Typical passwords: Vernam password, round robin password
Vernam password Vernam password is also known as one password at a time. That is, the key it uses can only be used once. Moreover, it is at least the same length as the encrypted message. Its generation is also random, and similar modular operations are used in encryption and decryption.
With the continuous maturity of mechanical and electromechanical technology, combined with the emergence of Telegraph and radio requirements, there is a special encryption equipment-rotation machine. As the name implies, it consists of a keyboard and a series of wheels. Each wheel is an arbitrary combination of 26 English letters. When each runner and moving gear is rotated, the original letters are all replaced with encrypted letters. Enigma encryption machine is the representative of the rotation code, the input letters through the wheel and moving gear to form a new circuit, corresponding to the encrypted letters in the light bulb.
03. The period of modern cryptography since the 1950s
At this stage, with the rapid development of wireless communication, wired communication and other communication means, combined with a solid mathematical theoretical foundation, cryptography began to become a science.
The second leap in cryptography: Diffie and Hellman published New Directions of Cryptography (a new direction of cryptography), which ushered in a new era of public key cryptography. Prior to this, the encryption key and decryption key used by the password were the same, that is, symmetric encryption. Public key cryptography means that the encryption key and decryption key used by the password are completely different, that is, asymmetric encryption.
Typical passwords: DES, AES, RSA, ECC
DESDES (data encryption Standard) is a symmetric cryptosystem encryption algorithm developed by IBM Company in 1972. it was determined as the Federal data processing Standard (FIPS) by the National Bureau of Standards of the Federal Government in 1977, and authorized to be used in non-secret government communications. It uses a key length of 56 bits and can generate 16 sub-keys. After grouping the message according to 64 bits, DES iterates with the subkey to generate ciphertext. However, with the improvement of computer computing power, the problem of too short DES key has become a security hidden danger, and the US government needs to find its alternative.
AESAES (Advanced encryption Standard), also known as Rijndael encryption algorithm, is a block encryption standard instead of DES adopted by the federal government of the United States. In 2006, AES has become one of the most popular algorithms in symmetric key encryption. The key length used is 128 bits, 192 bits and 256 bits. At present, it still plays a role in network information, e-commerce, database, hardware and other related fields.
In the year of RSA1977, Ron Rivest, Adi Shamir and Leonard Adleman of the United States first proposed a more perfect public key cryptosystem-RSA (composed of the first letters of the three surnames). The algorithm is based on the mathematical difficult problem of large prime factorization. It is one of the most widely used public key encryption schemes at present, and its mainstream key length is generally more than 1024 bits.
ECCECC (Elliptic Curve algorithm) was first proposed by Koblitz and Miller in 1985. The algorithm is based on the difficult mathematical problem of ellipse discrete logarithm. It uses encoding to convert the message into a point m on the elliptic curve (functional form: y ^ 2 = x ^ 3 + ax+b), and all operations are performed on the elliptic curve. Its advantage is that in some cases, it can use a shorter key than other encryption algorithms, providing an equal or higher level of security. The disadvantage is that encryption and decryption take a long time. The key length used by the mainstream is generally more than 160 bits.
04. Looking forward to the future, the domestic cryptographic algorithms recognized by the State Cryptography Bureau of China, including SM1, SM2, SM3 and SM4. Among them, SM1 is symmetrical encryption, the algorithm is not public, and is called through the interface of the encryption chip. SM2 is public key encryption and is implemented based on ECC. SM3 is used for message length compression. SM4 is symmetrical encryption, which belongs to the standard packet data algorithm of wireless local area network.
Looking forward to the future, with the rapid development of new technologies such as artificial intelligence, block chain and quantum communication, people put forward higher requirements for the security and application of passwords. The research of cryptography will enter a new stage, and cryptography will come to people with a new attitude. With artificial intelligence and block chain as application scenarios, various passwords against quantum attacks are waiting for people to delve into and discover step by step.
Conclusion well, the above is a general introduction to the development and application of cryptography. The document wants to use several passwords to simply encrypt the information to see if you really understand it.
Caesar code
Ciphertext: o r u b k e u a
Offset: 6
RSA
Ciphertext: 58 0
N = 3 * 5
E = 35
D = 3
Don't rush to look down at the answer.
Answer 1:iloveyou (I loveyou)
The answer is 2:5 2 0
This article comes from the official account of Wechat: ZTE documents (ID:ztedoc)
Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.
Views: 0
*The comments in the above article only represent the author's personal views and do not represent the views and positions of this website. If you have more insights, please feel free to contribute and share.
Continue with the installation of the previous hadoop.First, install zookooper1. Decompress zookoope
"Every 5-10 years, there's a rare product, a really special, very unusual product that's the most un
© 2024 shulou.com SLNews company. All rights reserved.