Abstract: the threshold proxy signature scheme allows the original signer to delegate a signature authority to the proxy group to cooperatively sign message on behalf of an original signer. In this paper, we propose a new scheme which includes the features and benefits of the RSA scheme. Also, we will evaluate the security of undeniable threshold proxy signature scheme with known signers. We find that the existing threshold proxy scheme is insecure against the original signer forgery. In this paper, we show the cryptanalysis of an existed scheme. Additional, we propose the secure, undeniable and known signers threshold proxy signature scheme which answers the drawback of an existed scheme. We also demonstrate that a threshold proxy signature suffers from a conspiracy of an original signer and a secret share dealer, that the scheme is commonly forgeable, and cannot offer undeniable. We claim that the proposed scheme offers the undeniable characteristic.

Sattar J. Aboud, “Secure Undeniable Threshold Proxy Signature Scheme” International Journal of Advanced Computer Science and Applications(IJACSA), 5(1), 2014. http://dx.doi.org/10.14569/IJACSA.2014.050109

@article{Aboud2014,
title = {Secure Undeniable Threshold Proxy Signature Scheme},
journal = {International Journal of Advanced Computer Science and Applications},
doi = {10.14569/IJACSA.2014.050109},
url = {http://dx.doi.org/10.14569/IJACSA.2014.050109},
year = {2014},
publisher = {The Science and Information Organization},
volume = {5},
number = {1},
author = {Sattar J. Aboud}
}