Polynomial Kernels and User Reductions for the Workflow Satisfiability Problem
The workflow satisfiability problem ( wsp ) is a problem of practical interest that arises whenever tasks need to be performed by authorized users, subject to constraints defined by business rules. We are required to decide whether there exists a plan —an assignment of tasks to authorized users—such...
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| Vydáno v: | Algorithmica Ročník 75; číslo 2; s. 383 - 402 |
|---|---|
| Hlavní autoři: | , , |
| Médium: | Journal Article |
| Jazyk: | angličtina |
| Vydáno: |
New York
Springer US
01.06.2016
|
| Témata: | |
| ISSN: | 0178-4617, 1432-0541 |
| On-line přístup: | Získat plný text |
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| Shrnutí: | The
workflow satisfiability problem
(
wsp
) is a problem of practical interest that arises whenever tasks need to be performed by authorized users, subject to constraints defined by business rules. We are required to decide whether there exists a
plan
—an assignment of tasks to authorized users—such that all constraints are satisfied. The
wsp
is, in fact, the
conservative constraint satisfaction problem
(i.e., for each variable, here called
task
, we have a unary authorization constraint) and is, thus,
NP
-complete. It was observed by Wang and Li (ACM Trans Inf Syst Secur 13(4):40,
2010
) that the number
k
of tasks is often quite small and so can be used as a parameter, and several subsequent works have studied the parameterized complexity of
wsp
regarding parameter
k
. We take a more detailed look at the kernelization complexity of
wsp
(
Γ
) when
Γ
denotes a finite or infinite set of allowed constraints. Our main result is a dichotomy for the case that all constraints in
Γ
are regular: (1) We are able to reduce the number
n
of users to
n
′
≤
k
. This entails a kernelization to size poly
(
k
)
for finite
Γ
, and, under mild technical conditions, to size poly
(
k
+
m
)
for infinite
Γ
, where
m
denotes the number of constraints. (2) Already
wsp
(
R
) for some
R
∈
Γ
allows no polynomial kernelization in
k
+
m
unless the polynomial hierarchy collapses. |
|---|---|
| ISSN: | 0178-4617 1432-0541 |
| DOI: | 10.1007/s00453-015-9986-9 |