INTERNATIONAL ISO/IEC STANDARD 18028-1

IS0/IEC18028-1:2006(E)Users and administrators should take special care to configure systems and applications associated withnetwork connections to disable functions that are not necessary in the circumstances. (For example, PCapplications could be configured so that macros are disabled by default, or require user confirmation beforeexecution of macros.)Further detail on malicious code protection is provided in ISO/IEC 17799, and will be in ISO/IEC 13335-2when published.13.10 Common Infrastructure Cryptographic Based Services13.10.1 PrefaceThe need for security and enhanced privacy is increasing as electronic forms replace their paper-basedcounterparts. The emergence of the Internet and the expansion of corporate networks to include access bycustomers and suppliers from outside an organization have accelerated the demand for solutions based oncryptography, to support authentication and VPNs, and to ensure confidentiality.13.10.2 Data Confidentiality over NetworksIn circumstances where preservation of confidentiality is important, encryption controls should be consideredto encrypt information passing over network connections. The decision to use encryption controls should takeaccount of relevant government laws and regulations, the requirements for key management, and thesuitability of the encryption mechanisms used for the type of network connection involved and the degree ofprotection required.Encryption mechanisms are standardized in ISO/IEC 18033. One commonly used encryption technique isknown as a block cipher, and ways of using block ciphers for encryption protection, known as modes ofoperation, are standardized in ISO/IEC 10116.13.10.3 Data Integrity over NetworksIn circumstances where preservation of integrity is important, digital signature and/or message integritycontrols should be considered to protect information passing over network connections. Digital signaturecontrols can provide similar protection to message authentication controls, but also have properties that allowthem to enable non-repudiation procedures (see Clause 13.10.4 below). The decision to use digital signatureor message integrity controls should take account of relevant government laws and regulations, relevantpublic key infrastructures, the requirements for key management, the suitability of the underlying mechanismsused for the type of network connection involved and the degree of protection required, and reliable andtrusted registration of users or entities associated with keys (certified where relevant) used in digital signatureprotocols.Message integrity controls, known as Message Authentication Codes (or MACs), are standardized inISO/IEC 9797. Digital signature techniques are standardized in ISO/IEC 9796 and ISO/IEC 14888.13.10.4 Non-RepudiationWhere there is a requirement to ensure that substantive proof can be provided that information was carried bya network, controls such as the following should be considered:— communication protocols that provide acknowledgement of submission,— application protocols that require the originator's address or identifier to be provided and check for thepresence of this information,— gateways that check sender and receiver address formats for validity of syntax and consistency withinformation in relevant directories,— protocols that acknowledge delivery from networks, and that allow the sequence of information to bedetermined.54 ©ISO/IEC2006-All rights reserved