US Patent 7061408 Concept for a secure data communication between electronic devices

An encoder for encoding a data word with a plurality of bits, wherein the data word is transmittable in parallel on a data bus, wherein one bit line is provided for each bit and wherein each bit may have one of two logical states, including a means for examining the data word in order to determine whether a first number of bits of the data word with a first logical state deviates from a second number of bits of the data word with a second logical state by more than a predetermined threshold, a means for changing the state of a bit of the data word in order to create an encoded data word in case the predetermined threshold is exceeded by the data word, and a means for detecting auxiliary information referring to the changed bit.