The Mobile agents are well suited for accessing contents of distributed web based applications including internet business. Such kinds of access must be secure enough enabling only authorized mobile agents to retrieve the contents from the distributed servers. This kind of security is provided by several algorithms including RSA based digital signature and elliptic curve digital signature cryptography. The main differences among the algorithms of the past literatures lie in the computational time of encryption and decryption of the keys used for encrypting and decrypting the content. In this paper we propose a modified hierarchical date constrained key management scheme which potentially reduces the overall computation time needed for key derivation and key signature check operations. Different algorithms are compared with our proposed mechanism and the experimental results show that the proposed method reduces the overall key derivation and key signature check computational time. © 2012 Published by Elsevier Ltd.