Privacy protection ridge regression

The invention provides a combined solution for privacy protection ridge regression, wherein homomorphic encryption and a Yao garbled circuit are used. A user in a system submits data which are encrypted on a condition of linear homomorphic encryption. Linear homomorphism is used for performing a first period of an algorithm, wherein only linear operation is required in the first period. In output of the first period, encrypted data are generated in a manner of independent from the number n of users. In a second period, the Yao garbled circuit is evaluated; homomorphic decryption of the Yao garbled circuit is firstly realized, and then residual parts of a regression algorithm are performed (shown in a diaphragm, wherein optimal implementation can prevent decryption in the garbled circuit). For the second step, the Yao garbled circuit solution is much faster than an existing fully homomorphic encryption solution. Therefore, through using linear homomorphism for processing a big data set and using the garbled circuit on onerous nonlinear calculation parts, advantages in two solutions can be simultaneously realized.