International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Functional Encryption for Attribute-Weighted Sums from k-Lin

Michel Abdalla , CNRS, ENS, PSL
Junqing Gong , East China Normal University
Hoeteck Wee , CNRS, ENS, PSL and NTT Research
DOI: 10.1007/978-3-030-56784-2_23 (login may be required)
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Conference: CRYPTO 2020
Abstract: We present functional encryption schemes for attribute-weighted sums, where encryption takes as input N attribute-value pairs (x_i,z_i) where x_i is public and z_i is private; secret keys are associated with arithmetic branching programs f, and decryption returns the weighted sum \sum_{i=1}^N f(x_i) z_i while leaking no additional information about the z_i's. Our main construction achieves (1) compact public parameters and key sizes that are independent of N and the secret key can decrypt a ciphertext for any a-priori unbounded N; (2) short ciphertexts that grow with N and the size of z_i but not x_i; (3) simulation-based security against unbounded collusions; (4) relies on the standard k-linear assumption in prime-order bilinear groups.
Video from CRYPTO 2020
  title={Functional Encryption for Attribute-Weighted Sums from k-Lin},
  author={Michel Abdalla and Junqing Gong and Hoeteck Wee},