Abstract: An apparatus including a photonic physically unclonable function (PUF) device for processing an initial optical mode distribution based on a challenge C and outputting a final optical mode distribution, the photonic PUF device includes optical mode waveguides for forming or supporting optical modes to which the initial optical mode distribution is provided and from which the final optical mode distribution is produced. Optical mode mixing layers are spaced apart along, and coupled to, the optical mode waveguides to mix the optical modes received by each optical mode mixing layer so that the optical mode distribution leaving each optical mode mixing layer is different to the optical mode distribution received by each optical mode mixing layer.

Abstract: An apparatus including: an input optical interface configured to receive a series of optical input signals each including photons; an encoder configured to encode a quantum key for distribution by encoding each of the series of received optical input signals with a measurable state; an attenuator configured to attenuate each of the encoded optical input signals to create a series of quantum optical signals; and an output optical interface configured to send the series of quantum optical signals to the remote apparatus via a quantum communication channel.

Abstract: An apparatus including: an input optical interface configured to receive a series of optical input signals each including photons; an encoder configured to encode a quantum key for distribution by encoding each of the series of received optical input signals with a measurable state; an attenuator configured to attenuate each of the encoded optical input signals to create a series of quantum optical signals; and an output optical interface configured to send the series of quantum optical signals to the remote apparatus via a quantum communication channel.