Authentication and Delegation
M. Abadi \Lambda M. Burrows \Lambda C. Kaufman y B. Lampson \Lambda
The authentication of users in distributed systems poses special problems
because users lack the ability to encrypt and decrypt. The same problems arise
when users wish to delegate some of their authority to nodes, after mutual
In most systems today, the user is forced to trust the node he wants to
use. In a more satisfactory design, the user carries a smartcard with sufficient
computing power to assist him; the card provides encryption and decryption
capabilities for authentication and delegation.
Authentication is relatively straightforward with a powerful enough smart
card. However, for practical reasons, protocols that place few demands on smart
cards should be considered. These protocols are subtle, as they rely on fairly
complex trust relations between the principals in the system (users, hosts, ser
vices). In this paper, we discuss a range of publickey smartcard protocols, and
analyze their assumptions and the guarantees they offer.