@inproceedings{bu2021fast, author = {Bu, Zhiqi and Gopi, Sivakanth and Kulkarni, Janardhan (Jana) and Lee, Yin Tat and Shen, Judy Hanwen and Tantipongpipat, Uthaipon}, title = {Fast and Memory Efficient Differentially Private-SGD via JL Projections}, booktitle = {NeurIPS 2021}, year = {2021}, month = {February}, abstract = {Differentially Private-SGD (DP-SGD) of Abadi et al. (2016) and its variations are the only known algorithms for private training of large scale neural networks. This algorithm requires computation of per-sample gradients norms which is extremely slow and memory intensive in practice. In this paper, we present a new framework to design differentially private optimizers called DP-SGD-JL and DP-Adam-JL. Our approach uses Johnson-Lindenstrauss (JL) projections to quickly approximate the per-sample gradient norms without exactly computing them, thus making the training time and memory requirements of our optimizers closer to that of their non-DP versions. Unlike previous attempts to make DP-SGD faster which work only on a subset of network architectures or use compiler techniques, we propose an algorithmic solution which works for any network in a black-box manner which is the main contribution of this paper. To illustrate this, on IMDb dataset, we train a Recurrent Neural Network (RNN) to achieve good privacy-vs-accuracy tradeoff, while being significantly faster than DP-SGD and with a similar memory footprint as non-private SGD. The privacy analysis of our algorithms is more involved than DP-SGD, we use the recently proposed f-DP framework of Dong et al. (2019) to prove privacy.}, url = {http://approjects.co.za/?big=en-us/research/publication/fast-and-memory-efficient-differentially-private-sgd-via-jl-projections/}, }