The chip, which protects data by generating a random sequence of numbers from photons, replaces the current system of key distribution based on mathematical algorithms.
Quantum cryptography works with photons, which are generated and coded by an optical array. The security of the data is said to be guaranteed as photons generate completely random keys. The mathematical formulae used in the past, which could be decrypted with enough time and effort, will soon be obsolete.
Once the optical array has sent the light particles to the recipient via optic-optic cable, each communication partner uses a detector to measure certain properties of the photons.
The values are then compared using a communication protocol via the internet. If they match, the chip takes over the processing and uses the results of the measurements to generate a tap-proof key.
The message is not transferred until this key is in place and any attempt to listen to a message when generating a key will be registered, as it will cause photons to be changed or destroyed. If the chip registers that a third-party is trying to listen in, it generates a new key. This process is repeated until it is certain that no one is listening in. The keys are used immediately in the chip to encrypt or decrypt the data, and then they are deleted.
Despite being an effective technology, Siemens cautions that it will be two years before it is ready for series production. However, the prototype of the quantum cryptography chip is already available, and the corresponding fibre-optic network for chip-based data transfer will be presented in October 2008 at Siemens IT Solutions and Services in