A keyboard input device includes a processor repeatedly executing a scan routine to detect key press events while masking the events from an external monitoring means. The keyboard input device has a number of finger-activatable keys, each connected at the intersection of row signal lines and column signal lines, which are in turn connected to the processor. The processor systematically activates the rows and randomly activates the columns. A key press event causes the key's associated row and column to create a closed switch. The processor monitors the columns for a signal forced on pairs of rows. Obfuscating signals forced onto the columns inhibit detection of the key press event signals by an external source.
System And Method For Multiplication Modulo (2N+1)
Donald Matthew - Campbell CA Susan K. Langford - Sunnyvale CA
Compaq Computer Corporation - Cupertino CA
A system and method are provided for performing modulo multiplication of two numbers N bits long with a modulus of 2. sup. N +1, where the resulting modulus is determined without a need to perform successive reductions. Without a need to perform successive reductions, a hardware implementation does not require a divider circuit.