Nandini Bhattad

Privacy Without Regret: Differentially Private Inference-Time Alignment

Private Inference-Time Pessimism (PrivITP) is introduced, which combines $\chi^2$-regularized rejection sampling with a two-phase Gaussian mechanism, and achieves ex-post $(\epsilon,\delta)$-DP with a privacy cost independent of the number of responses, cleanly decouples the regularization parameter from the privacy parameter, and attains the skyline up to a noise-inflation term.