Issue No. 05 - September/October (1986 vol. 3)
P.A. Suhler , University of Texas at Austin
For every piece of business software sold, at least one illegal copy exists. This article describes and classifies software-protection methods.
P.A. Suhler, N. Bagherzadeh, M. Malek, N. Iscoe, "Software Authorization Systems", IEEE Software, vol. 3, no. , pp. 34-41, September/October 1986, doi:10.1109/MS.1986.234396