Researchers Find Quantum Random Number Cryptosystems Need Tweaking to Prevent Steganographic-like Cryptographic Channels

In classical and quantum secure communication practical randomness is incomplete

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+  Random bit sequences are key ingredients of various tasks in modern life and especially in secure communication. In a new study researchers have determined that generating true random bit sequences, classical or quantum, is an impossible mission. Based on these findings, they have demonstrated a new method of classified secure communication.

“According to the fundamental principles of quantum physics, the randomness of quantum random bit generators is expected to be perfect. In practice, however, this perfect quantum randomness may be diminished by many experimental imperfections, said Prof. Kanter. “Hence, a sequence generated by a quantum number generator ultimately has to be certified by statistical tests which can differentiate between original quantum guaranteed sequences and spurious ones. However, the newly-discovered incompleteness of practical randomness is expected to disrupt even quantum random number generators.”

+  Researchers at Bar-Ilan University demonstrate that long sequences with certified randomness by the US National Institute of Standard and Technology (NIST) are far from being truly random. Their work demonstrates that a large fraction of non-random bits can be systematically embedded in such bit sequences without negatively affecting their certified randomness. This discovery leads to a new type of classified secure communication between two parties where even the existence of the communication itself is concealed.

+  “Our strategy aims to quantify the maximal amount of information that can be systematically embedded in a certified random bit sequence, without harming its certification,” said Ph.D. students Shira Sardi and Herut Uzan, the key contributors to the research.

+  Using such a strategy, the level of randomness can be quantified beyond the binary certification. In addition, since the information is systematically embedded in the bit sequence, the approach offers a new cryptosystem, similar to steganography, where the existence of any communication is completely concealed.

Source:  Bar-Ilan University,  In classical and quantum secure communication practical randomness is incomplete…

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