Modes of Operation
The QuintessenceLabs quantum cryptographic system has four distinct modes of operation:
True one-time Pad
The one-time pad is the only encryption method, proven mathematically, to be unbreakable. Until now, true one-time-pad operation has suffered from an inability to transmit the decoding key at suitable bit-rates. QuintessenceLabs QKD implements a true one-time pad in real time to ensure absolute and everlasting data confidentiality.
Key Expansion
When very high rates of data encryption are necessary, key expansion can be used in which the QKD key material is expanded through a deterministic random bit generator (DRBG) algorithm to produce the one time pad key. This mode reduces the amount of QKD key material necessary for encryption, yet still provides exceptionally high data confidentiality.
Hybrid key Generation
Hybrid key generation is the method employed by most quantum cryptographic technologies on the market today principally due to the limited data rates they can operate in. It does not provide the absolute security of the true one-time-pad, or key expansion but does offer an enhancement over conventional data encryption methods.
The QuintessenceLabs QKD system can also operate in a Hybrid key generation mode to integrate quantum key distribution with classical, AES, data encryption. This mode of operation may be preferred when interoperation with legacy encryption systems is desired.