Title
One-Tape Turing Machine And Branching Program Lower Bounds For Mcsp
Abstract
For a size parameter s: N -> N, the Minimum Circuit Size Problem (denoted by MCSP[s(n)]) is the problem of deciding whether the minimum circuit size of a given function f : {0, 1}(n) -> {0, 1} (represented by a string of length N := 2(n)) is at most a threshold s(n). A recent line of work exhibited "hardness magnification" phenomena for MCSP: A very weak lower bound for MCSP implies a breakthrough result in complexity theory. For example, McKay, Murray, and Williams (STOC 2019) implicitly showed that, for some constant mu(1) > 0, if MCSP[2(mu 1.n)] cannot be computed by a one-tape Turing machine (with an additional one-way read-only input tape) running in time N-1.01, then P not equal NP.In this paper, we present the following new lower bounds against one-tape Turing machines and branching programs:1. A randomized two-sided error one-tape Turing machine (with an additional one-way read-only input tape) cannot compute MCSP[2(mu 2.n)] in time N-1.99, for some constant mu(2) > mu(1).2. A non-deterministic (or parity) branching program of size o(N-1.5/ logN) cannot compute MKTP, which is a time-bounded Kolmogorov complexity analogue of MCSP. This is shown by directly applying the Neciporuk method to MKTP, which previously appeared to be difficult.3. The size of any non-deterministic, co-non-deterministic, or parity branching program computing MCSP is at least N1.5-o(1).These results are the first non-trivial lower bounds for MCSP and MKTP against one-tape Turing machines and non-deterministic branching programs, and essentially match the best-known lower bounds for any explicit functions against these computational models.The first result is based on recent constructions of pseudorandom generators for read-once oblivious branching programs (ROBPs) and combinatorial rectangles (Forbes and Kelley, FOCS 2018; Viola 2019). En route, we obtain several related results:1. There exists a (local) hitting set generator with seed length (O) over tilde(root N) secure against read-once polynomial-size non-deterministic branching programs on N-bit inputs.2. Any read-once co-non-deterministic branching program computing MCSP must have size at least 2((Omega) over tilde (N)).
Year
DOI
Venue
2021
10.4230/LIPIcs.STACS.2021.23
38TH INTERNATIONAL SYMPOSIUM ON THEORETICAL ASPECTS OF COMPUTER SCIENCE (STACS 2021)
Keywords
DocType
Volume
Minimum Circuit Size Problem, Kolmogorov Complexity, One-Tape Turing Machines, Branching Programs, Lower Bounds, Pseudorandom Generators, Hitting Set Generators
Conference
187
ISSN
Citations 
PageRank 
1868-8969
0
0.34
References 
Authors
20
4
Name
Order
Citations
PageRank
Mahdi Cheraghchi181.60
Shuichi Hirahara237.48
Dimitrios Myrisiotis300.34
Yuichi Yoshida446944.88