【導(dǎo)讀】指出密鑰的長度、多重DES算法、算法的安全管理、弱密鑰等安全性問題必須給予重視。應(yīng)用中還無法將這種加密算法完全破解掉，因此也被美國政府作為限制出口的一種技術(shù)，它目前仍被廣泛使用，具有較高的安全性。于加密又可用于解密。到的原則下，利用F函數(shù)及對合等運算，充分利用非線性運算。DES以64位為分組對數(shù)。每組64位，最后一組若不足64位以“0”補齊。密鑰通常表示為64位的數(shù)，其中極少量的數(shù)被認為是弱密鑰，但能容易地避開。它們，所有的保密性依賴于密鑰。和右半部分，各32位長。初始置換和對應(yīng)的末置換并不影響DES. 它的主要目的是為了更容易地將明文與密文數(shù)據(jù)以字節(jié)大放入DES芯片中。位，DES密鑰由64位減至56位，56位密鑰被分成兩部分，前28位為C0，后28位為D0。然是安全的，但提醒使用者不要使用低于16－圈的DES，特別是10－圈以下的DES。針對DES算法，專家們的共識是采用3重DES

　　

【正文】 attention. Modern cryptography features is algorithm can open. The key is how to protect the confidentiality of their keys, and the key is broken secret key. How can get hacking The security of the system, this system according to the director of the actual use of key length and the sensitive degree of protection of information, important degree and the actual place security environment system of degree, in bad with sufficient safety coefficient conditions from determine its key and certificate change cycle length. Meanwhile, will have abandoned key and certificate in black library archive, away for future use. Key change cycle right security strategy is system can safe operation of the system39。s safety protection, is the most important and the most managers of daily tasks. weak keys In DES algorithm 12 and a half exists weak key and four weak keys. Because the key in the son produced process, the key is divided into 2 parts, if this 2 parts into full 0 or total 1, so each wheel produces daughter keys are the same, and when keys are all 0 or 1, or half full 1 or 0, can produce weak keys, or half a weak the safety of keys, DES algorithm will bee poor. In setting key should avoid weak keys, or half a weak key to appear. 4 DES use of the algorithm After since DES algorithm, caused promulgated by academic and corporate attention. Many manufacturers soon produce realize DES algorithm Hardware products, users in the market to buy high speed and cheap DES hardware products, to start using it after the important data encryption himself, thus greatly promote the use of a password techniques. DES algorithm entry parameters have 3: Key specific, Data, Mode. One Key specific for 8 byte 64 bits, which is the Key。 DES algorithm work Data also for 8 byte 64bit, is to be encrypted or message decrypted Data。 Mode for DES way of working, have two kinds: encryption and decryption. DES algorithm is how it works: such as Mode for encryption, then use the Data to Key specific Data encrypt Data and generate the password form (64 bits)。 the output as DES Such as Mode for decryption, from the password form to Key specific Data declassified, restore Data for the Data related forms (64 bits) as the output results. DES In munication work, the parties have agreed on the ends of the agreement in munication, Key specific source point of core data with Key specific, and then taking DES encrypted password form in public munication work (such as work) in the end of transmission to munication work, data arrived at their destination, with the same Key specific data of password decryption, he portrays plain code forms of core data. So, then guaranteed the core data (such as PIN, MAC, etc) in public munication work security and reliability of the transmission of [3]. Through regularly in the munication work in the source end and purpose in the switch to the new Key specific, can further improve the data privacy, this is now the financial trading work vogue. In development system, Microsoft provides DES public key encryption class, use it, and we can prepare yourself Standard DES encryption algorithm. In any one unit, the programmer as long as this program can design of scattered discrete files for encryption loses. If you want to exchange the data and other units, due to the use of public algorithm, only need to provide each other key and algorithm specification can, use very convenient. References: [1] Wilkinson j eigenvalue problem. Computer data in a puter work ─ cryptography secrecy and security: the first 3 edition [M]. Beijing: tsinghua university press, 2021. [2]. WuWenLing block cipher FengDengGuo, the design and analysis [M]. Beijing: tsinghua university Press, 2021. [3] DuanWei YangMao phosphorus, ge yong, postgraduate for PhD. The password algorithms and its application in military munication [J].journal of fire Force mand and control, 2021 (3) : 6871.