US Patent 8074077 Securing circuit designs within circuit design tools

A method of securing a circuit design can include generating a string including a plurality of elements. The plurality of elements can include elements of design information selected from within the circuit design and at least one security element indicating whether the circuit design is protected. The method further can include permuting the plurality of elements of the string, encrypting the permuted string using a key shared with a circuit design tool, and including the permuted and encrypted string within the circuit design.