1、BRITISH STANDARD BS ISO/IEC 7064:2003 Information technology Security techniques Check character systems ICS 35.040 BS ISO/IEC 7064:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 21 March 2003 BSI 21 March 2003 ISBN 0 580 41440 X Nation
2、al foreword This British Standard reproduces verbatim ISO/IEC 7064:2003 and implements it as the UK national standard. It supersedes BS 6541:1985 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee IST/33, Security techniques, which has the responsibility
3、 to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards
4、 Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard doe
5、s not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European devel
6、opments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO/IEC title page, pages ii to v, a blank page, pages 1 to 13 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Am
7、endments issued since publication Amd. No. Date Comments Reference number ISO/IEC 7064:2003(E)INTERNATIONAL STANDARD ISO/IEC 7064 First edition 2003-02-15 Information technology Security techniques Check character systems Technologies de linformation Techniques de scurit Systmes de caractres de cont
8、rle BSISO/IEC7064:2003BSISO/IEC7064:2003iiISO/IEC 6074:0203()E ISO/IE002 C3 All rihgts erservde iiiContents 1Scope 1 2Termsanddefinitions 1 3Symbolsandnotation 2 4Typesofsystems 2 4.1 Pure systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 4.2 H
9、ybrid systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 5Complianceanddesignation 2 5.1 Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 5.2 Check character generating products . .
10、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 5.3 Checking products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 5.4 System designation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 6Sp
11、ecificationofpuresystems 3 6.1 Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 6.2 Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 6.3 Check character position . . . . . .
12、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 7Computationalmethodsforpuresystemswithonecheckcharacter 4 7.1 Pure system recursive method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 7.1.1 Computation . . . . . . . . . . . . . . . . . .
13、. . . . . . . . . . . . . . . . . . . . . . . . . . 4 7.1.2 Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.2 Pure system polynomial method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.2.1 Computation . . . .
14、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.2.2 Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 8Computationalmethodsforpuresystemswithtwocheckcharacters 6 8.1Computation6 8.2Exampleusingrecursivemethod.6
15、 8.3 Example using polynomial method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 8.4 Simplied procedure for ISO/IEC 7064, MOD 9710 . . . . . . . . . . . . . . . . . . . . . . . . . . 7 9Specificationforhybridsystems 7 9.1 Formula . . . . . . . . . . . . . . . . . . . .
16、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 9.2 Check character position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 10Computationalmethodforhybridsystems 8 10.1Hybridsystemrecursivemethod.8 10.1.1 Computation . . . . . . . . . . . . . .
17、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 10.1.2Example.8 Annex A (informative) Criteria for the selection of check character systems for applications . 10 Annex B (informative) Check character systems for other alphabets . 12 Bibliography 13 BSISO/IEC7064:2003iiiISO/IEC 6074:020
18、3()E vi ISO/IE002 C3 All rihgts erservdeForeword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development o
19、f International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in
20、liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of the joint
21、technical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. Attention
22、 is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. ISO/IEC 7064 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommi
23、ttee SC 27, IT Security techniques. This first edition of ISO/IEC 7064 cancels and replaces ISO 7064:1983, which has been technically revised. Note, however, that implementations which comply with ISO 7064:1983 will be compliant with ISO/IEC 7064:2003. BSISO/IEC7064:2003ivISO/IEC 6074:0203()E ISO/IE
24、002 C3 All rihgts erservde vIntroduction The need for standardization of check character systems was determined by the following considerations: a)ofthemultitudeofsystemsinuse,manyhaveverysimilarcharacteristics,andmuchofthevarietyfailsto provideanysignicantbenet; b)fewoftheexistingsystemshavebeentho
25、roughlyveriedmathematicallyandseveralhaveseriousdefects; c) the variety of systems undermines the economics of products which generate or validate check characters, and frequentlypreventsthecheckingofinterchangeddata. Therefore a small set of compatible systems were selected to cope with various app
26、lication needs; they were validated, and within the constraints of each application, oer high protection against typical transcription and keying errors. Existing check character systems as specied in ISO 2108, ISO 2894 and ISO 6166 are used in special application elds (ISO 2894 has been withdrawn).
27、 These do not however, achieve the error detection rate of the systems specied in this International Standard. Annex A summarizes the criteria to be considered when selecting a check character system specied in this International Standard for a particular application. Annex B provides an example of
28、a method by which this standard may be applied to an alphabet that has more than 26 characters. BSISO/IEC7064:2003vETNIRNAANOITLSTANDRAD ISO/EIC 002:46073)E( Information technology | Security techniques | Check character systems 1 Scope 1.1 This International Standard species a set of check characte
29、r systems capable of protecting strings against errors which occur when people copy or type data. The strings may be of xed or variable length and may have character sets which are a) numeric (10 digits: 0 to 9); b) alphabetic (26 letters: A to Z); and c) alphanumeric (letters and digits). Embedded
30、spaces and special characters are ignored. 1.2 This International Standard species confor- mance requirements for products described as gener- ating check characters or checking strings using the systems given in this International Standard. 1.3 These check character systems can detect: a) all singl
31、e substitution errors (the substitution of a single character for another, for example 4234“ for 1234)“; b) all or nearly all single (local) transposition errors (thetranspositionoftwosinglecharacters, either adjacentorwithonecharacterbetweenthem, for example 12354“ or 12543“ for 12345“); c) all or
32、nearly all circular shift errors (circular shifts of the whole string to the left or right); d) a high proportion of double substitution er- rors (two separate single substitution errors in the same string, for example 7234587“ for 1234567)“; and e) a high proportion of all other errors. 1.4 This In
33、ternational Standard excludes systems designed specically to: a) permitbotherrordetectionandautomaticcorrec- tion; b) detect deliberate falsication; and c) check strings interchanged solely between ma- chines. 1.5 This International Standard is for use in infor- mation interchange between organizati
34、ons. It is also strongly recommended for use in internal information systems. 2 Terms and denitions For the purposes of this International Standard, the following terms and denitions apply. 2.1 check character: Added character which may be used to verify the accuracy of the string by a mathematical
35、relationship to that string. 2.2 check character system: Set of rules for gen- erating check characters and checking strings in- corporating check characters. 2.3 supplementary check character: Check character which does not belong to the charac- ter set of the strings which are to be protected. 2.4
36、 modulus: Integer used as a divisor of an integer dividendinordertoobtainanintegerremainder. 2.5 congruence: Property of a set of integers which dier from each other by a multiple of the mod- ulus. Congruence is indicated by the symbol . For example, 39 6 (mod11) indicates that 39 and 6 are congruen
37、t with respect to the modulus 11, i.e., 396=33, which is a multiple of 11. 2.6 radix: Base of a geometric progression. c EI/OSIC0203 lAlirghtserresved1 BSISO/IEC7064:20031EI/OSIC:46072003)E( 3Symbolsandnotation ThroughoutISO/IEC7064thefollowingsymbolsand notation are used. a i Numerical value of the
38、 character in position i. i Index of the character position. M Modulus. n Number of characters in a string, including the check character. P j , S j , V Integers which are used in the calculation of the check character to store an intermediate result. r Radix. w j Weight for the polynomial method. X
39、, Supplementary check characters. := A symbol denoting the set equal to operation used in the procedural specications of check characters, which indicates that the value of the integer on the left side of the symbol shall be made equal to the value of the expression on the right side of the symbol.
40、A symbol denoting congruence (see Clause 2.5). k M A symbol denoting the unique integer between 1 andM thatistheremainderafterdividingbyM; if this remainder is zero then the value M shall be substituted. j M+1 A symbol denoting the unique integer between 0 and M that is the remainder after dividing
41、by M +1; the remainder is never zero after this op- eration. (modM) A symbol denoting the unique integer be- tween 0 and M 1 that is the remainder after dividing by M. 4 Types of systems ThisInternationalStandardspeciestwotypesofsys- tems: a) pure systems (Clauses 6, 7 and 8) and b) hybrid systems (
42、Clauses 9 and 10). 4.1 Pure systems The pure systems are listed in Table 1 and specied inClauses6, 7and8. Theyeachuseasinglemodulus for all stages of the calculation. 4.2 Hybrid systems ThehybridsystemsarelistedinTable2andspecied in Clauses 9 and 10. The hybrid systems each use two moduli in the cal
43、culation. One modulus is equal to, and the other is one greater than, the number of characters in the character set of the string to be protected. These hybrid systems always provide a check character within the character set of the string to be protected. 5 Compliance and designation 5.1 Strings St
44、rings protected by one of the systems specied in this International Standard for the relevant applica- tion comply with this International Standard. 5.2Checkcharactergeneratingproducts 5.2.1 Products (implemented either in software or hardware) that are described as generating check characterstothis
45、InternationalStandardwithoutfur- ther qualication shall be capable of generating check characters for all systems in this International Stan- dard. 5.2.2 Thedescriptionofproductswhichdonotgen- eratecheckcharactersforallthesystemsinthisInter- national Standard shall specify those systems which they d
46、o cover, for example generates check charac- ters in accordance with ISO/IEC 7064, MOD 112“. 5.3 Checking products 5.3.1 Products (implemented either in software or hardware) that are described as checking strings to this International Standard without further qualica- tion shall be capable of using
47、 all the systems in this International Standard. 5.3.2 The description of products which check strings using only certain of the systems in this Inter- national Standard shall specify those systems which they do cover, for example checks strings using ISO/IEC 7064, MOD 112“. 5.4 System designation 5.4.1 Normally the full designation of each system as given in Tables 1 and 2 shall be used, for example ISO/IEC 7064, MOD 112“. NOTE | Abbreviations to forms such as MOD 11“ will create confusion with the similar systems using modulus 11. 2c EI/OSIC0203 lAlirghtserresvde BSISO/IEC7064:20032
