I agree the example is weird, but that's literally what the paper says: "In the training phase, it takes as input an encrypted training data and outputs an enc

I agree the example is weird, but that's literally what the paper says: "In the training phase, it takes as input an encrypted training data and outputs an encrypted model without using the decryption key. In the prediction phase, it uses the encrypted model to predict results on new encrypted data." Figure 1 further implies that the results must be decrypted. This is the typical operational setting of homomorphic ML.