@article{589,
  author = {Osmanbey Uzunkol},
  title = {Comments on “verifiable outsourced attribute-based signature scheme”},
  abstract = {Ren and Jiang recently published a “verifiable outsourced attribute-based signature scheme” in Multimedia Tools and Applications. In this note, we first provide two attacks on the verifiability of the semi-signatures of this scheme by showing that a malicious signing-cloud service provider (S-CSP) can always cheat the signer unlike the authors’ claim. Moreover, one of these attacks also implies that an untrusted S-CSP can always forge signatures contrary to the claimed unforgeability against chosen message attacks. Therefore, this scheme unfortunately does not satisfy the main security properties for a delegated signature scheme.},
  year = {2019},
  booktitle = {Multimedia Tools and Applications },
  journal = {Multimedia Tools and Applications },
  volume = {78},
  pages = {11735-11742, },
  month = {2019/05/01},
  isbn = {1573-7721},
  url = {https://doi.org/10.1007/s11042-018-6725-7},
  doi = {10.1007/s11042-018-6725-7},
}