Stiffness is the resistance a material or structure offers against deformation. A stiff object bends, compresses, or twists less under the same force than a flexible one. In mechanics, stiffness helps determine how a surface stores and returns energy, which is why it is closely related to bounce, vibration, and impact behavior.
In cyber security, stiffness matters in hardware and physical protection. Enclosures, circuit boards, mounts, and sensor housings need enough stiffness to resist prying, flexing, and misalignment. Low stiffness can make devices easier to tamper with, damage connectors, or disturb precision parts such as antennas, optics, or cryptographic hardware. Defenders often increase stiffness with stronger frames, reinforcement, potting, or rigid mounting so systems stay aligned and tamper-resistant. Attackers may try to exploit weak structures by bending, cracking, or forcing access through parts that deform too easily.