determines the set of valid key sizes for the symmetric cryptographic algorithms 確定對稱加密算法的有效密鑰大小設(shè)置。
the paper discusses the development of web, browser / server mode conception and the content and mechanism of network security based on web, and also describes the basic conception and system of cipher theory, symmetric-based data encryption standard and advanced encryption standard and asymmetric-based rsa . it presents a detailed design of secrecy net of digital government, and advances a des-and-rsa-based security model of information exchange, which makes use of symmetric cryptographic algorithm to encrypt plaintext, and introduces public-key algorithm rsa to encrypt session key to compose digital envelope and to realize digital signature 本文論述了web的發(fā)展及其browser/server模式概念,以及基于web的網(wǎng)絡(luò)安全的內(nèi)容與機制;闡述了密碼學(xué)的基本概念、分類,對稱密鑰密碼體制des與aes以及公開密鑰密碼體制rsa;最后,利用一種基于des和rsa的信息交換安全模型,詳細地給出了一個數(shù)字政府的保密網(wǎng)系統(tǒng)設(shè)計方案。