Optical encryption terminal, cryptography key distribution system and method of generating cryptography keys in a cryptography key distribution system

A cryptography key distribution system, comprising:

• a first optical encryption terminal configured to transform optical input signals into optical output signals in accordance with a first optical encryption pattern provided at the first optical encryption terminal;
• a second optical encryption terminal configured to transform optical input signals into optical output signals in accordance with a second optical encryption pattern provided at the second optical encryption terminal, the first and second optical encryption terminals being optically coupled so as to mutually exchange optical output signals;
• a first source of electromagnetic radiation configured to provide the first optical encryption terminal with first input signals of electromagnetic radiation;
• a second source of electromagnetic radiation configured to provide the second optical encryption terminal with second input signals of electromagnetic radiation;
• a first detection element configured to detect at least one first radiometric and/or photometric quantity associated with first optical output signals of the first optical encryption terminal, the first optical output signals being based on the second input signals being successively transformed by the second and first optical encryption terminals;
• a second detection element configured to detect at least one second radiometric and/or photometric quantity associated with second optical output signals of the second optical encryption terminal, the second optical output signals being based on the first input signals being successively transformed by the first and second optical encryption terminals;
• a first electronic processing unit coupled to the first detection element, the first electronic processing unit being configured to determine a first cryptographic key signal on the basis of at least one first radiometric and/or photometric quantity detected by the first detection element;
• and
• a second electronic processing unit coupled to said second detection element, the second electronic processing unit being configured to determine a second cryptographic key signal on the basis of at least one detected second radiometric and/or photometric quantity detected by the second detection element.

A method of generating cryptographic keys in a cryptography key distribution system having a first optical encryption terminal and a second optical encryption terminal, the method comprising:

• providing the first optical encryption terminal with electromagnetic radiation of a first source of electromagnetic radiation as first optical input signals;
• transforming the first optical input signals into first optical output signals in accordance with a first optical encryption pattern formed at the first optical encryption terminal;
• providing the second optical encryption terminal with the first optical output signals as second optical input signals;
• transforming the second optical input signals into second optical output signals in accordance with a second optical encryption pattern formed at the second optical encryption terminal;
• detecting at least one first radiometric and/or photometric quantity associated with the second optical output signals;
• and
• determining a first cryptographic key on the basis of the at least one detected first radiometric and/or photometric quantity.