摘要 |
In a method for controlled program execution by a portable data carrier, the value of a status counter (ZZ) is altered during execution of each controlled section (36.x) of an executed program (30) in order to reflect the processing of the respective controlled section (36.x); when executing a jump instruction (42.x), which causes one or more controlled sections (36.x) to be skipped, the value of the status counter (ZZ) is altered as if the skipped controlled sections (36.x) had been executed and the value of the status counter (ZZ) is compared at at least one test point (38) with at least one admissible value. A portable data carrier has corresponding features. The invention provides reliable protection against manipulations of the portable data carrier and is also suitable for application in executing complex programs.
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