Jamming is denial of service. If the transmission medium is flooded with a high noise floor, digital signal processors will fail to decode any valid values from the band the carrier signal transmits on. Authentic signatures have no utility if excessive noise outshines the entirety of the signal.
No one can check any signatures, if the signed message cannot reach an audience.
Perhaps an aperture could prevent omni-directional cross-talk and interference, forcing a receiver to only listen from a specific, selected line-of-sight source, but to simulate warfare, what if the enemy really does manage to completely destroy a resource?
A genuine disruption keeps everyone honest in the spirit of the exercise. It’s really down. Not just “what if”? No peeking. No cheating.