We provide a general model and two modular constructions of our novel primitive, supporting the class of linear functions. On our way, we establish various novel building blocks. Most interestingly, we formally define the notion and present a construction of homomorphic proxy re-encryption, which may be of independent interest. The latter allows users to encrypt messages under their own public keys, and a proxy can re-encrypt them to a receiver's public key (without knowing any secret key), while also being able to evaluate functions on the ciphertexts. The resulting re-encrypted ciphertext then holds an evaluation of the function on the input messages.
Category / Keywords: public-key cryptography / data aggregation, verifiable computation, homomorphic encryption, proxy re-encryption, homomorphic signatures, homomorphic MACs, proxy re-authenticators Original Publication (with major differences): Financial Cryptography and Data Security 2017 Date: received 3 Feb 2017 Contact author: david derler at iaik tugraz at Available format(s): PDF | BibTeX Citation Version: 20170210:150534 (All versions of this report) Short URL: ia.cr/2017/086 Discussion forum: Show discussion | Start new discussion