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Has the program been altered?
Author(s) -
Wichmann B. A.
Publication year - 1981
Publication title -
software: practice and experience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 70
eISSN - 1097-024X
pISSN - 0038-0644
DOI - 10.1002/spe.4380110811
Subject(s) - pascal (unit) , computer science , computer program , turbo pascal , programming language , digital computer , algorithm , theoretical computer science , magnetic tape , character (mathematics) , computer engineering , computer hardware , mathematics , digital recording , geometry
Abstract It is often essential to know if a computer program has been altered. If the text has been provided on magnetic tape and subsequently loaded onto another computer with possible changes in the character set, the problem becomes more difficult. This paper proposes the use of a ‘parity check’ as used in digital data transmission. An implementation of this algorithm in Pascal is given together with details of how a Pascal source text can be checked for alterations using the algorithm.