Collateral impact of closure deletion

Determine the unrelated-memory cost of closure deletion when removing an entire stored object because any of its source turns is deleted.

Background

The benchmark deletes memory objects by closure: when a source turn is removed, every object derived from that turn is also removed. This procedure can eliminate content unrelated to the protected secret, particularly in memory systems that consolidate or summarize multiple source turns into shared objects.

The paper explicitly identifies the resulting collateral loss of unrelated memory as an unresolved question, separate from the source-level deletion costs measured in the experiments. Characterizing this cost would help assess the practical utility and safety of dedicated erasure methods for long-term LLM-agent memory.

References

Closure deletion also removes a whole object when any of its source turns goes; what it costs in unrelated memory is a separate question, which we leave to future work.

— MemCut: Every Secret Leaves a Trail in the Long-Term Memory of LLM Agents  (2610.21405 - Zhang et al., 15 Oct 2026) in Appendix B.2, Section “Derivation strength”