When proving to a third party that a software system is free from critical memory bugs, software vendors often face the problem of having to reveal their source code, so that the third party can scan the source code using static analysis tools. However, such transparency poses a significant threat to vendors, as the source code typically contains proprietary algorithms, core technical innovations, or trade secrets, exposing them to potential intellectual property risks. In this paper, we present a novel solution that offers a balance between transparency and code privacy, so that software vendors can provide minimal source code information but can justify the sufficiency of bug detection. To this end, we propose DIReducer, which reduces source code information, a.k.a. debug information, from non-stripped binaries while preserving its utility for memory bug detection. DIReducer consists of two components: selective pruning and type minimization. The former eliminates redundant debug information, and the latter is proved to be NP-hard and minimizes type-related debug information by reducing it to the classic set-cover problem, which offers feasible and near-optimal solutions. Experimental results show that we can reduce over 90% of debug information while maintaining similar bug detection capability compared to using full debug information.