Solving Positive Linear Programs with Differential Privacy
Pith reviewed 2026-05-07 12:02 UTC · model grok-4.3
The pith
Differentially private solvers for positive LPs that approximate solutions with bounded constraint violations and improve on prior instance-dependent and new data-independent guarantees.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
We give private solvers that return approximate solutions while violating only a controlled number of constraints. Our algorithms improve the prior instance-dependent guarantees, and also yield new data-independent bounds that depend only on the dimension.
Load-bearing premise
The focus on positive linear programs (nonnegative coefficients and variables) in the high-sensitivity constraint-private regime of Hsu et al., where full constraint satisfaction under privacy is impossible.
read the original abstract
We study differentially private approximation algorithms for positive linear programs (LPs with nonnegative coefficients and variables), focusing on the fundamental families of packing, covering, and mixed packing-covering formulations. We focus on the high-sensitivity, constraint-private regime of Hsu-Roth-Roughgarden-Ullman (ICALP 2014), where neighboring instances may differ by an arbitrary single constraint, so one cannot hope to approximately satisfy every constraint under privacy. We give private solvers that return approximate solutions while violating only a controlled number of constraints. Our algorithms improve the prior instance-dependent guarantees, and also yield new data-independent bounds that depend only on the dimension. Our techniques involve a dense multiplicative weights update method developed from a regularized dual viewpoint, which we analyze in a way that exploits structure specific to positive LPs.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper develops differentially private approximation algorithms for positive linear programs (packing, covering, and mixed packing-covering) in the high-sensitivity constraint-private model. In this regime, neighboring instances differ by a single arbitrary constraint, making it impossible to approximately satisfy all constraints under privacy. The algorithms return approximate solutions while violating only a controlled number of constraints, improving prior instance-dependent guarantees and providing new data-independent bounds that depend only on the dimension. The central technique is a dense multiplicative-weights update method derived from a regularized dual formulation that exploits the nonnegativity structure of positive LPs.
Significance. If the results hold, the paper makes a solid contribution to differentially private optimization. It advances the state of the art by tightening instance-dependent violation bounds and adding clean dimension-only bounds that are independent of the specific data. The regularized-dual derivation of the dense MWU method is a technically interesting approach that leverages positive-LP structure in a natural way and may generalize. The work is well-motivated by the known impossibility results in the constraint-private model and builds directly on standard LP duality and privacy definitions without circularity or hidden parameters.
minor comments (2)
- [Abstract] The abstract and introduction would benefit from a brief, self-contained definition or example of what 'dense' MWU means in this context and why the regularization is required to obtain the stated bounds.
- Notation for the positive LP families (packing, covering, mixed) and the precise privacy model (neighboring relation on constraints) should be introduced with a single displayed equation block early in the paper for reference.
Simulated Author's Rebuttal
We thank the referee for the positive and constructive review. We are pleased that the referee recognizes the paper's contributions to differentially private solvers for positive LPs in the constraint-private model, the improvements to instance-dependent violation bounds, the new dimension-dependent data-independent bounds, and the technical value of the regularized dual derivation of the dense MWU method. The referee's assessment aligns with our view that the work is well-motivated by known impossibilities and builds directly on standard LP duality without circularity.
Circularity Check
No significant circularity in derivation chain
full rationale
The paper derives private solvers for positive LPs via a dense MWU method from a regularized dual viewpoint, exploiting nonnegativity and standard LP duality plus privacy definitions. No load-bearing step reduces by construction to a fitted parameter, self-definition, or self-citation chain. The cited Hsu et al. (2014) regime is external prior work defining the model, not an internal reduction. The instance-dependent and dimension-only bounds follow from the analysis without renaming known results or smuggling ansatzes. The central claim remains independently verifiable against external benchmarks.
Axiom & Free-Parameter Ledger
axioms (2)
- domain assumption Linear programs have nonnegative coefficients and variables (positive LPs)
- domain assumption Neighboring instances differ by an arbitrary single constraint in the high-sensitivity regime
discussion (0)
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