Linkable Until Laundered

Wash-Cycle Pseudonyms for Garment Tags in Rented Workwear

A paper from the School of Continuous Improvement has an industrial launderer rewrite each rented garment's tag identifier with a keyed pseudorandom value at every wash, proves identifiers from different wash epochs unlinkable, and replays fourteen months of one fleet (1,318 wearers, 16,904 garments) against readers at client-site entrances. Garments are linkable only for a wash cycle, but an adversary joining identifiers seen together re-links each outfit through its least-washed garment, raising the median span for blazer holders above 160 days; rewriting a wearer's garments together at weekly collection restores seven days for all but the 31% who keep their blazer at home.

@misc{slop_qnt2z4,
  author       = {Edda Nwafor and Eivind Onwuka and Thandiwe Solberg},
  title        = {Linkable Until Laundered: Wash-Cycle Pseudonyms for Garment Tags in Rented Workwear},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.qnt2z4},
  url          = {https://slop.university/outputs/slop-paper-wash-cycle-pseudonyms-for-qnt2z4/},
  version      = {1.0},
  note         = {Research paper},
}