Massachusetts Institute of Technology

Nationaluniversity of Ireland, Maynooth

Alejandro Cohen

Muriel Medard

Kenneth R Duffy

Amit Solomon

Derya Malak

Rafael Gregorio Lucas D'oliveira

Salman Salamatian

A system and method provide a hybrid communication scheme that achieves high communication rates with post-quantum computational security guarantees. Messages to be securely communicated are first mixed using an individually secure encoding, such as a linear network code, and some of the encoded messages are further encrypted. The encrypted and unencrypted messages are sent via different communications channels. Each unencrypted message becomes almost as secure as the encrypted messages because of the pre-mixing, since decoding any one of the messages requires all of the messages, including the encrypted messages. Thus, a very few encrypted messages may be used, allowing the rate of communication to approach one as the number of channels increases. This is particularly beneficial when a classical public-key cryptosystem can only be used in part of the data transmitted or stored, in the presence of noisy channels, in distributed data storage, and other applications.

Network coding-based post-quantum cryptography

Techniques are disclosed for an adaptive and causal random linear network coding (AC-RLNC) with forward error correction (FEC) for a communication channel with delayed feedback. An example methodology implementing the techniques includes transmitting one or more coded packets in a communication channel, determining a channel behavior of the channel, and adaptively adjusting a transmission of a subsequent coded packet in the first channel based on the determined channel behavior. The communication channel may be a point-to-point communication channel between a sender and a receiver. The channel behavior may be determined based on feedback acknowledgements provided by the receiver. The subsequent coded packet may be a random linear combination of one or more information packets.

Adaptive causal network coding with feedback

Described are concepts, systems, devices and methods that enhance decoding performance of channels subject to correlated noise. The concepts, systems, devices and methods can be used with any combination of codes, code-rates and decoding techniques. In embodiments, a continuous realization of effective noise is estimated from a lead channel by subtracting its decoded output from its received signal. This estimate is then used to improve the accuracy of decoding of an otherwise orthogonal channel that is experiencing correlated effective noise. In this approach, channels aid each other through the post-decoding provision of estimates of effective noise. In some embodiments, the lead channel is not pre-determined, but is chosen dynamically based on which of a plurality of decoders completes first, or using soft information including an estimate of effective noise that is least energetic or most likely to have occurred.

Noise recycling

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Brookline, MA, United States of America

Alejandro Cohen