Watermarking based protection of virtual component blocks

A computerized method for protecting a circuit design from unauthorized use, the method comprising:

• receiving the circuit design associated with an I/O signature, the I/O signature embedded into the circuit design using a finite state machine,
• the finite state machine including a set of free input configurations, each free input configuration being without a specified output or destination state,
• a path selected from among the set of free input configurations comprising a series of state transitions, the series of state transitions comprising an input sequence,
• output values assigned to the series of state transitions collectively comprising an output signature, the input sequence and the output signature collectively comprising the I/O signature;
• checking a database for the existence of the I/O signature, the database comprising a plurality of I/O signatures, wherein each of the plurality of I/O signatures is embedded in a different circuit design vendor product;
• and
• authenticating the source of the circuit design if the I/O signature exists in the database.

A computer program product embodied on computer readable medium, the computer readable medium having stored thereon a sequence of instructions which, when executed by a processor, causes the processor to execute a method for protecting a circuit design from unauthorized use, the method comprising:

• receiving the circuit design associated with an I/O signature, the I/O signature embedded into the circuit design using a finite state machine,
• the finite state machine including a set of free input configurations, each free input configuration being without a specified output or destination state,
• a path selected from among the set of free input configurations comprising a series of state transitions, the series of state transitions comprising an input sequence,
• output values assigned to the series of state transitions collectively comprising an output signature, the input sequence and the output signature collectively comprising the I/O signature;
• checking a database for the existence of the I/O signature, the database comprising a plurality of I/O signatures, wherein each of the plurality of I/O signatures is embedded in a different circuit design vendor product;
• and
• authenticating the source of the circuit design if the I/O signature exists in the database.