The Concept and the Architecture 5. The structure of an S-program as implemented in Prototype II is shown in Fig. 5. The pricing information for a S-program is contained in its tariff section. A verification routine, described below, is embedded in the body of the S-program.
Execution is aborted if the verification routine detects any inconsistency in the tariff section.
A key used by the authentication routine in the S-program body. This key is checked by the coprocessor. A key used to encrypt the machine instructions in the body of the S-program. An encrypted block of instructions is transferred to the coprocessor, where it is decrypted using this key and then executed. The amount of memory required within the coprocessor for executing the S-program.