|  Yu H L, Zheng D D, Zhao B Y, Zheng W M. Understanding user behavior in large-scale video-on-demand systems. In Proc. the 1st ACM SIGOPS/EuroSys European Conf. Computer Systems, April 2006, pp.333-344. Goldmann M, Kreitz G. Measurements on the spotify peer-assisted music-on-demand streaming system. In Proc. IEEE Int. Conf. Peer-to-Peer Computing, September 2011, pp.206-211. Mambo M, Usuda K, Okamoto E. Proxy signatures:Delegation of the power to sign messages. IEICE Trans. Fundamentals of Electronics Communications and Computer Sciences, 1996, E79-A(9):1338-1354. Mambo M, Usuda K, Okamoto E. Proxy signatures for delegating signing operation. In Proc. the 3rd ACM Conf. Computer and Communications Security, March 1996, pp.48-57. Lee B, Kim H, Kim K. Secure mobile agent using strong non-designated proxy signature. In Proc. the 6th Australasian Conf. Information Security and Privacy, July 2001, pp.474-486. Kim S, Park S, Won D. Proxy signatures, revisited. In Proc. the 1st Int. Conf. Information and Communications Security, November 1997, pp.223-232. Hwang M S, Tzeng S F, Chiou S F. An improvement of strong proxy signature and its applications. In Proc. the Int. Conf. Security and Cryptography, July 2008, pp.95-98. Chen X F, Zhang F G, Kim K. ID-based multi-proxy signature and blind multisignature from bilinear pairings. In Proc. KⅡSC, Nov. 2003, pp.11-19. Zhang F G, Safavi-Naini R, Lin C Y. New proxy signature, proxy blind signature and proxy ring signature schemes from bilinear pairing. IACR Cryptology ePrint Archive, 2003. https://eprint.iacr.org/2003/104.pdf, Jan. 2018. Zhang F G, Safavi-Naini R, Susilo W. An efficient signature scheme from bilinear pairings and its applications. In Proc. the 7th Int. Workshop on Theory and Practice in Public Key Cryptography, March 2004, pp.277-290. Li X X, Chen K F, Li S Q. Multi-proxy signature and proxy multi-signature schemes from bilinear pairings. In Proc. the 5th Int. Conf. Parallel and Distributed Computing:Applications and Technologies, December 2004, pp.591-595. Yi L J, Bai G Q, Xiao G Z. Proxy multi-signature scheme:A new type of proxy signature scheme. Electronics Letters, 2000, 36(6):527-528. Sun H M. Design of time-stamped proxy signatures with traceable receivers. IEE Proceedings-Computers and Digital Techniques, 2000, 147(6):462-466. Schuldt J C N, Matsuura K, Paterson K G. Proxy signatures secure against proxy key exposure. In Proc. the 11th Int. Workshop on Practice and Theory in Public-Key Cryptography, March 2008, pp.141-161. Das M L, Saxena A, Gulati V P. An efficient proxy signature scheme with revocation. Informatica, 2004, 15(4):455-464. Seo S H, Shim K A, Lee S H. A mediated proxy signature scheme with fast revocation for electronic transactions. In Proc. the 2nd Int. Conf. Trust Privacy and Security in Digital Business, August 2005, pp.216-225. Liu Z H, Hu Y P, Zhang X S, Ma H. Provably secure multiproxy signature scheme with revocation in the standard model. Computer Communications, 2011, 34(3):494-501. Lu E J L, Hwang M S, Huang C J. A new proxy signature scheme with revocation. Applied Mathematics and Computation, 2005, 161(3):799-806. Fuchsbauer G, Pointcheval D. Anonymous proxy signatures. In Proc. the 6th Int. Conf. Security and Cryptography for Networks, September 2008, pp.201-217. Laberteaux K P, Haas J J, Hu Y C. Security certificate revocation list distribution for VANET. In Proc. the 5th Int. Workshop on Vehicular Inter-NET Working, September 2008, pp.88-89. Chaib N, Lagraa N, Yagoubi M B. EPRV:Efficient pseudonym revocation in VANETs. Ad Hoc & Sensor Wireless Networks, 2017, 38(1/2/3/4):199-225. Caballero-Gil C, Molina-Gil J, Hernández-Serrano J, León O, Soriano-Ibañez M. Providing k-anonymity and revocation in ubiquitous VANETs. Ad Hoc Networks, 2016, 36:482-494. Studer A, Shi E, Bai F, Perrig A. Tacking together efficient authentication, revocation, and privacy in VANETs. In Proc. the 6th Annual IEEE Communications Society Conf. Sensor Mesh and Ad Hoc Communications and Networks, June 2009. Xu S M, Yang G M, Mu Y, Ma S. Proxy signature with revocation. In Proc. the 21st Australasian Conf. Information Security and Privacy, July 2016, pp.21-36. Naor D, Naor M, Lotspiech J. Revocation and tracing schemes for stateless receivers. In Proc. the 21st Annual Int. Cryptology Conf., August 2001, pp.41-62. Halevy D, Shamir A. The LSD broadcast encryption scheme. In Proc. the 22nd Annual Int. Cryptology Conf., August 2002, pp.47-60. Dodis Y, Fazio N. Public key broadcast encryption for stateless receivers. In Proc. ACM CCS-9 Workshop Digital Rights Management, November 2002, pp.61-80. Goldwasser S, Micali S, Rivest R L. A digital signature scheme secure against adaptive chosen-message attacks. SIAM Journal on Computing, 1988, 17(2):281-308. Boneh D, Shen E, Waters B. Strongly unforgeable signatures based on computational Diffie-Hellman. In Proc. the 9th Int. Conf. Theory and Practice in Public-Key Cryptography, April 2006, pp.229-240. Boneh D, Lynn B, Shacham H. Short signatures from the Weil pairing. In Proc. the 7th Int. Conf. the Theory and Application of Cryptology and Information Security, December 2001, pp.514-532. Boneh D, Boyen X, Goh E J. Hierarchical identity based encryption with constant size ciphertext. In Proc. the 24th Annual Int. Conf. the Theory and Applications of Cryptographic Techniques, May 2005, pp.440-456. Huang X Y, Mu Y, Susilo W, Zhang F G, Chen X F. A short proxy signature scheme:Efficient authentication in the ubiquitous world. In Proc. Int. Conf. Embedded and Ubiquitous Computing, December 2005, pp.480-489. Huang X Y, Susilo W, Mu Y, Wu W. Proxy signature without random oracles. In Proc. the 2nd Int. Conf. Mobile Adhoc and Sensor Networks, December 2006, pp.473-484.