Techniques are disclosed for defensive routing of guard wires for security-critical wires in an integrated circuit (IC). Defensive routing provides a routing-centric and preventive layout-level defense against IC fabrication time attacks against security-critical wires within an IC. An example methodology implementing the techniques includes identifying at least one security-critical wire in an IC design, identifying at least one unblocked surface of the identified at least one security-critical wire, and guarding the identified at least one surface of the identified at least one security-critical wire with a guard wire. In one example, the guard wire may be a natural guard wire. In another example, the guard wire may be a synthetic guard wire.

An integrated circuit (IC) structure includes a device layer including a security-critical wire and a metal layer disposed over the device layer. The metal layer includes at least one wire and an IC porthole. The IC porthole has a perimeter that defines a shape such that, when the perimeter of the IC porthole is projected onto the device layer, the projection of the IC porthole perimeter includes at least a segment of the security-critical wire, and the at least one wire in the metal layer does not overlap the security-critical wire within the projection of the IC porthole perimeter to thereby allow post-fabrication optical inspection of the security-critical wire through the IC porthole.

Techniques are disclosed for defensive routing of guard wires for security-critical wires in an integrated circuit (IC). Defensive routing provides a routing-centric and preventive layout-level defense against IC fabrication time attacks against security-critical wires within an IC. An example methodology implementing the techniques includes identifying at least one security-critical wire in an IC design, identifying at least one unblocked surface of the identified at least one security-critical wire, and guarding the identified at least one surface of the identified at least one security-critical wire with a guard wire. In one example, the guard wire may be a natural guard wire. In another example, the guard wire may be a synthetic guard wire.

An integrated circuit (IC) structure includes a device layer including a security-critical wire and a metal layer disposed over the device layer. The metal layer includes at least one wire and an IC porthole. The IC porthole has a perimeter that defines a shape such that, when the perimeter of the IC porthole is projected onto the device layer, the projection of the IC porthole perimeter includes at least a segment of the security-critical wire, and the at least one wire in the metal layer does not overlap the security-critical wire within the projection of the IC porthole perimeter to thereby allow post-fabrication optical inspection of the security-critical wire through the IC porthole.