Non-invasive attack

Nanophotonics is a promising candidate for meeting the above requirements for two reasons (1) a signal can be transferred by the dressed photon exchange between nanometric particles without using any wires and (2) a non-invasive attack is impossible because the signal intensity is fixed by the energy dissipation inside the nanometric particles [30]. This section reviews the principles, operations, and applications of these nanophotonic devices. 

Because the long-wavelength approximation is not valid due to the localized nature of the dressed photon (refer to Sect. 1.2), an electron in the nanometric particle can be excited even to an electric dipole-forbidden energy level as a result of the dressed photon exchange between closely spaced nanometric particles, which enables novel nanometer-scale wireless optical devices with dimensions beyond the diffraction-limit, low energy consumption, and resistance to non-invasive attacks. 

---