Quantum Internet would enable data to travel securely around the globe using photons that obey physical laws and thus enable future-proof encryption capabilities.
Key technology behind this development is entanglement, which physicists have demonstrated over long distances of optical fibre. Next comes an infrastructure of “repeaters” capable of amplifying and reading these photonic states.
Authentication
One way of protecting communications on a quantum internet is through authenticating participants. This involves verifying that any photon-pulses sent from one party are truly from them without any alteration taking place during transit.
An important challenge lies in achieving high levels of success during an authentication procedure over long distances, for instance ensuring that photons created by true quantum repeaters can travel over a network with only minor percentages of error.
Researchers at Argonne National Laboratory and Fermi Laboratory have made great strides towards this goal. For instance, they have demonstrated the sharing of entangled qubits over a 52-mile fiber link, an essential building block of any future quantum internet. Furthermore, they have successfully demonstrated quantum teleportation using supercooled clouds of rubidium atoms which serve as quantum memory between two labs separated by approximately 10 kilometers.
Encryption
Quantum encryption will become much stronger, protecting sensitive data against hacking for an extended period. But to qualify as quantum secure, encrypted information must remain unhacked over an extended timeframe.
Quantum key distribution (QKD) provides the means for this. A transmitter encodes digital keys containing either “0” or “1”, along with basis types (“X” or “Y”) into single photon pulses for transmission; receivers then decode this coded information by measuring each photon pulse and deciphering back into original bit information.
QKD faces one major drawback, however: quantum states cannot be amplified using traditional optical-fiber signal repeaters. Therefore, networks using QKD must rely on trusted nodes at multiple points to achieve secure encryption entanglement transmission over long distances – nodes like those developed by US Department of Energy’s Q-Next lead partner Argonne National Laboratory have silicon vacancy center nodes that can receive and store entangled qubits while compensating for signal loss so entanglement can travel further distances allowing long distance transmission of entanglement before passing it onwards to another network node containing another key exchange.
Decryption
Today’s sensitive data travels through fiber-optic cables and other channels along with digital “keys” that unlock it – but these keys themselves are vulnerable to interception as they’re encoded as bits – pulses of electrical or optical signals representing 1s and 0s that hackers can read to copy data without leaving a trace behind.
Contrast this with a quantum network which transmits only qubits. Furthermore, its weird properties — specifically that their particles can become entangled across long distances– provide extra security against interceptions and hacking attempts.
While a comprehensive quantum internet with functional quantum computers may still be several years away, researchers at DOE’s Argonne and Fermi national labs are already hard at work developing building blocks to make this futuristic technology a reality. They include developing quantum repeaters that exploit entanglement, speeding up transmission routes by improving delivery speed for qubits along their routes while correcting errors as they arise and optimizing error correction methods along these routes.
Quantum key distribution
Existing cryptography systems rely heavily on difficulty of solving extremely hard problems; quantum computing (PQC) renders such schemes obsolete, prompting industry transition efforts towards PQC as an essential way of protecting data across mission-critical networks.
QKD uses photons – light particles which carry binary data one or zero across optical fibres – as bit carriers. Each photon sent from sender to receiver is encoded with either an X or Y basis type that receiver then decodes by measuring individual photon detectors to detect individual photon positions.
Bob and Alice can compare a predetermined set of their remaining bits, and if they match this indicates that Eve, an eavesdropper known as, hasn’t gained any information regarding the original key transmission. This provides the foundation for device-independent protocols which make no assumptions about the equipment used while employing prepare-and-measure steps to eliminate all side channels, while using bell inequalities violations for robust verification systems.
