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Continuous-variable quantum authentication of physical unclonable keys

View Article: PubMed Central - PubMed

ABSTRACT

We propose a scheme for authentication of physical keys that are materialized by optical multiple-scattering media. The authentication relies on the optical response of the key when probed by randomly selected coherent states of light, and the use of standard wavefront-shaping techniques that direct the scattered photons coherently to a specific target mode at the output. The quadratures of the electromagnetic field of the scattered light at the target mode are analysed using a homodyne detection scheme, and the acceptance or rejection of the key is decided upon the outcomes of the measurements. The proposed scheme can be implemented with current technology and offers collision resistance and robustness against key cloning.

No MeSH data available.


Schematic representation of the authentication protocol.The output of the laser is injected into a single-mode fiber (SMF) and then split, using an unbalanced fiber coupler (UFC), into a large fraction that serves as the local oscillator (LO) and a small fraction that serves as the probe in the verification. The phase of the probe relative to the LO is adjusted using a phase modulator (PM), and the challenge is obtained by modulating the wavefront of the probe using a phase-only spatial-light modulator (SLM). The challenge is then focused on the key, and the scattered (reflected) light is coupled out by means of a polarizing beam splitter (PBS), which ensures the collection of light that has undergone multiple scattering in the key23. The phase mask of the SLM is adjusted so that the scattered light is focused on one of the transverse modes of the output plane, where it is coupled to a SMF. The quadratures of the electric field of the scattered light are measured using a standard homodyne detection (HD) set-up involving a phase modulator in the LO path, a balanced fiber coupler (BFC) and two photodiodes. The laser source, the interrogation chamber and the HD chamber are considered to be well-separated and connected via SMFs.
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f1: Schematic representation of the authentication protocol.The output of the laser is injected into a single-mode fiber (SMF) and then split, using an unbalanced fiber coupler (UFC), into a large fraction that serves as the local oscillator (LO) and a small fraction that serves as the probe in the verification. The phase of the probe relative to the LO is adjusted using a phase modulator (PM), and the challenge is obtained by modulating the wavefront of the probe using a phase-only spatial-light modulator (SLM). The challenge is then focused on the key, and the scattered (reflected) light is coupled out by means of a polarizing beam splitter (PBS), which ensures the collection of light that has undergone multiple scattering in the key23. The phase mask of the SLM is adjusted so that the scattered light is focused on one of the transverse modes of the output plane, where it is coupled to a SMF. The quadratures of the electric field of the scattered light are measured using a standard homodyne detection (HD) set-up involving a phase modulator in the LO path, a balanced fiber coupler (BFC) and two photodiodes. The laser source, the interrogation chamber and the HD chamber are considered to be well-separated and connected via SMFs.

Mentions: A realization of the proposed EAP is shown in Fig. 1, and consists of the probe state preparation set-up, the interrogation chamber, and the homodyne-detection (HD) set-up (chamber). Except for the HD, the scheme is similar to the wavefront-shaping set-up used for the control of light scattered by a disordered multiple-scatering medium (to be referred to hereafter as the key)16171819202122232425. The laser beam at wavelength λ is split into two parts: a weak probe that is sent to the wavefront shaping set-up, and a strong local oscillator, which will serve as a reference in the HD of the scattered light. The key is assumed to have a slab geometry with thickness L and mean free path . In the diffusive regime, i.e. for , where Labs is the absorption length, light undergoes multiple scattering events in the key, and the process can be described in terms of a finite number of discrete input and output transverse spatial modes26272829. Using a phase-only spatial light modulator (SLM), one can control the phases of the incoming modes, thereby directing coherently the main part of the scattered light into a prescribed outgoing mode (to be referred to hereafter as the target mode)16171819202122232425. For a given key, one can select different target modes by changing accordingly the phase mask of the SLM. Moreover, different output transverse modes can be addressed by a single-mode fiber (SMF), which can be translated on the output (optical) plane in a controlled manner, provided that the overall imaging system is optimized so that the diameter of a single speckle grain matches the diameter of the mode of the SMF2324.


Continuous-variable quantum authentication of physical unclonable keys
Schematic representation of the authentication protocol.The output of the laser is injected into a single-mode fiber (SMF) and then split, using an unbalanced fiber coupler (UFC), into a large fraction that serves as the local oscillator (LO) and a small fraction that serves as the probe in the verification. The phase of the probe relative to the LO is adjusted using a phase modulator (PM), and the challenge is obtained by modulating the wavefront of the probe using a phase-only spatial-light modulator (SLM). The challenge is then focused on the key, and the scattered (reflected) light is coupled out by means of a polarizing beam splitter (PBS), which ensures the collection of light that has undergone multiple scattering in the key23. The phase mask of the SLM is adjusted so that the scattered light is focused on one of the transverse modes of the output plane, where it is coupled to a SMF. The quadratures of the electric field of the scattered light are measured using a standard homodyne detection (HD) set-up involving a phase modulator in the LO path, a balanced fiber coupler (BFC) and two photodiodes. The laser source, the interrogation chamber and the HD chamber are considered to be well-separated and connected via SMFs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5385567&req=5

f1: Schematic representation of the authentication protocol.The output of the laser is injected into a single-mode fiber (SMF) and then split, using an unbalanced fiber coupler (UFC), into a large fraction that serves as the local oscillator (LO) and a small fraction that serves as the probe in the verification. The phase of the probe relative to the LO is adjusted using a phase modulator (PM), and the challenge is obtained by modulating the wavefront of the probe using a phase-only spatial-light modulator (SLM). The challenge is then focused on the key, and the scattered (reflected) light is coupled out by means of a polarizing beam splitter (PBS), which ensures the collection of light that has undergone multiple scattering in the key23. The phase mask of the SLM is adjusted so that the scattered light is focused on one of the transverse modes of the output plane, where it is coupled to a SMF. The quadratures of the electric field of the scattered light are measured using a standard homodyne detection (HD) set-up involving a phase modulator in the LO path, a balanced fiber coupler (BFC) and two photodiodes. The laser source, the interrogation chamber and the HD chamber are considered to be well-separated and connected via SMFs.
Mentions: A realization of the proposed EAP is shown in Fig. 1, and consists of the probe state preparation set-up, the interrogation chamber, and the homodyne-detection (HD) set-up (chamber). Except for the HD, the scheme is similar to the wavefront-shaping set-up used for the control of light scattered by a disordered multiple-scatering medium (to be referred to hereafter as the key)16171819202122232425. The laser beam at wavelength λ is split into two parts: a weak probe that is sent to the wavefront shaping set-up, and a strong local oscillator, which will serve as a reference in the HD of the scattered light. The key is assumed to have a slab geometry with thickness L and mean free path . In the diffusive regime, i.e. for , where Labs is the absorption length, light undergoes multiple scattering events in the key, and the process can be described in terms of a finite number of discrete input and output transverse spatial modes26272829. Using a phase-only spatial light modulator (SLM), one can control the phases of the incoming modes, thereby directing coherently the main part of the scattered light into a prescribed outgoing mode (to be referred to hereafter as the target mode)16171819202122232425. For a given key, one can select different target modes by changing accordingly the phase mask of the SLM. Moreover, different output transverse modes can be addressed by a single-mode fiber (SMF), which can be translated on the output (optical) plane in a controlled manner, provided that the overall imaging system is optimized so that the diameter of a single speckle grain matches the diameter of the mode of the SMF2324.

View Article: PubMed Central - PubMed

ABSTRACT

We propose a scheme for authentication of physical keys that are materialized by optical multiple-scattering media. The authentication relies on the optical response of the key when probed by randomly selected coherent states of light, and the use of standard wavefront-shaping techniques that direct the scattered photons coherently to a specific target mode at the output. The quadratures of the electromagnetic field of the scattered light at the target mode are analysed using a homodyne detection scheme, and the acceptance or rejection of the key is decided upon the outcomes of the measurements. The proposed scheme can be implemented with current technology and offers collision resistance and robustness against key cloning.

No MeSH data available.