Control of the current taken by an electronic circuit used in reading the security code from a device such as a bankers card of portable telephone to mask the period during which the code is read, but to reduce the masking period

摘要

Procedure in which a masking current is applied to variations in the current taken by an electronic circuit during a fraction of the total time (ti-tj) but which includes any period where confidential data is being read from a EEPROM memory. An Independent claim is made for an electronic circuit for implementing the above procedure.