First Advisor
Fang Song
Date of Award
5-26-2017
Document Type
Thesis
Degree Name
Bachelor of Science (B.S.) in Physics and University Honors
Department
Physics
Subjects
Quantum theory, Hashing (Computer science), Collisions (Nuclear physics)
DOI
10.15760/honors.421
Abstract
This work proves an improved lower bound for the quantum query complexity of collision- finding in hash functions whose images are distributed according to a non-uniform distribution. Recent work by [TTU16] applied the leftover hash lemma to show that at least Omega(2k/9) quantum queries are necessary to find a collision when the image distribution has min-entropy k. In comparison, a result by [Zha15] implies that Omega(2k/3) quantum queries are necessary if the distribution is uniform. In this paper the lower bound complexity of [Zha15] is extended directly to the non-uniform case using a chain of reductions which convert collisions in min-entropy k distributions into collisions in the uniform distribution with constant probability. This result shows a minimum security guarantee for hash functions under more general assumptions in which the image distribution may not be uniform.
Rights
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Persistent Identifier
http://archives.pdx.edu/ds/psu/20427
Recommended Citation
Balogh, Marko, "An Improved Lower Bound for the Quantum Query Complexity of Collision Finding in Hash Functions with Non-Uniformly Distributed Images" (2017). University Honors Theses. Paper 425.
https://doi.org/10.15760/honors.421