Defensive IC Routing

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.