Issue No.04 - July/August (2003 vol.15)
<p><b>Abstract</b>—Tzeng proposes a time-bound cryptographic key assignment scheme for access control in a partial-order hierarchy. In this paper, we show that Tzeng's scheme is insecure against the collusion attack whereby three users conspire to access some secret class keys that they should not know according to Tzeng's scheme.</p>
Access control, key assignment, RSA, collusion attack.
Xun Yi, "Security of Tzeng's Time-Bound Key Assignment Scheme for Access Control in a Hierarchy", IEEE Transactions on Knowledge & Data Engineering, vol.15, no. 4, pp. 1054-1055, July/August 2003, doi:10.1109/TKDE.2003.1209023