Abstract: A quantum key distribution device comprises an input signal path receiving a plurality of optical input signals from a transmitter device, an output signal path connected to the input signal path at a first end and emitting a plurality of first optical output signals at a second end, and a detector signal path connected to the input signal path at a third end and comprising a photon detector device at a fourth end opposite to the third end. The photon detector detects optical input signals from the transmitter device, and the quantum key distribution device establishes a shared quantum cryptographic key with the transmitter device based on the detected optical input signals. The input signal path forms an input path of a Mach-Zehnder interferometer, and the output signal path and the detector signal path form output paths of the Mach-Zehnder interferometer.

Abstract: A method and system for encrypted messaging includes first and second client devices and a quantum key device having a quantum random number generator. The generator provides a first quantum random signal, and the key device provides a symmetric first master key from the first quantum random signal. The master key is transmitted to the first client device and stored. The key device uses the master key to generate an encrypted package by encrypting one of a plurality of keys. The key device generates a second encrypted package. The first pairing key is provided to the first client device by decrypting the first encrypted package using the first master key and providing the first pairing key in the second client device by decrypting the second encrypted package using the second master key to establish an encrypted connection between the first and second client devices.

Abstract: A system and method incudes generating a first target cryptocurrency key pair and a corresponding first target cryptocurrency address. A first cryptocurrency asset is transferred from to the first target cryptocurrency address employing a first cryptocurrency protocol, while providing a first password in a first user device and first user data assigned to a first user with a first vault asset corresponding to the at least one first cryptocurrency asset. The first password is transmitted from the first device to the server employing a first quantum key distribution protocol. Upon verification of the first key, a second vault asset is removed from the first user data, and a second target cryptocurrency key pair and a corresponding second target cryptocurrency address of a second cryptocurrency asset corresponding to the second vault asset are transmitted from the server to the first user device employing the first quantum key distribution protocol.