Abstract: Manbo proposed full delegation, partial delegation and delegation by warrant, three types of proxy signature scheme in 1996. The proxy signature scheme is used for an original signer delegating his capability to a designated signer, called a proxy signer. Compared to Manbo`s scheme basing on discrete logarithm, Shao proposed a proxy signature scheme using the RSA cryptosystem in 2003. After Shao`s scheme, M-S Hwang, S-F Tzeng and C-S Tsai proposed a proxy signature scheme basing on elliptic curves in 2004. This work proposes two novel proxy signature schemes basing on QR (Quadratic Residues). The first proxy signature scheme is full delegation method and the second one is delegation by warrant. Furthermore, the system administrator (SA) is introduced in the second scheme and the signature developed by Fan is applied. The SA designates qualified signers to sign warrants or documents. Those two novel proxy signature schemes basing on QR can take advantage of the QR property to achieve low-computing effects and to provide the same security level equal to those proxy signature basing on discrete logarithm, RSA or elliptic curves.
Chen I-Te and Yi-Shiung Yeh , 2005. Proxy Signature Scheme Basing on QR. Asian Journal of Information Technology, 4: 541-549.