Table 5:

MIA effectiveness under weight-decaying on Enron dataset with LoRA-FT (w/ weight decay factor 0.5).

Model Init.	AUC w/o ${\mathit{\theta }}_{\text{ref}}$	@0.01FPR	@0.1FPR	AUC	Tr-PPL	Val-PPL
Benign	54.37%	2.40%	38.32%	73.48%	20.18	20.19
PreCurious	55.18%	15.57%	85.63%	92.70%	16.61	17.07