A self-synchronous scrambler/descrambler and method for operating same are disclosed. A self-synchronous scrambler/descrambler comprises an M-bit Scrambler State memory for retaining M previously scrambled/descrambled bits, a SOP/EOP Zero Inserter for receiving replacing certain bytes of the bus word with a value of zero, a Mid-Packet Word Logic for scrambling/descrambling the received bits using the previously scrambled/descrambled bits from the M-bit Scrambler State memory; and a Barrel Shifter for rotating the M-bit Scrambler State memory backwards. The method for scrambling/descrambling bits, comprising receiving a bus word, replacing certain bytes of the bus word, scrambling/descrambling bits of the bus word by exclusive-ORing with previously scrambled/descrambled bits, retaining the scrambled/descrambled bits of the bus word; and rotating the scrambled/descrambled bits of the bus word backwards an amount.