Protocols for Secure Communication in Wireless Sensor Networks

214 Chapter 6. Integrity-Preserving Communications
DNS and store an additional record that provides, for each address domain, the
URL of a site that contains the message fingerprints. Thereby, domain owners
are free to administer their own servers.
6.8 Related Work
To our knowledge, interleaved authentication schemes have been independently
conceived independently from our work [180, 181, 182] by several authors [71,
206].
The first record is by Goodrich [71], which has been extended later [72].
In his scheme, for each node x, there is a key k(x) that is shared among all
nodes in the neighbourhood of x, excluding x itself. A node adjacent to x uses
k(x) to add an authentication code to a message before it sends it to x. When
x passes the message (including the authentication code) on to another one of
its neighbours, the receiver can verify that x has not modified the message.
The difference to Canvas is the use of a single key shared by all neighbours to
protect against the possible compromise of a node (x). In this approach, x can
forward a message according to local requirements. It is not required that the
sender of a message knows the path further down of x. Canvas requires this
knowledge and thus implies additional communication. Goodrich applies the
technique to securing the set-up of routing tables.
The second independent record is by Zhu et al. [206], who proposed interleaved
authentication for integrity checking of messages that are passed along
a path from sensor nodes towards a base station. Similar to our work, they extended
the scheme for interleavings of more than two hops, which allows for
protection against colluding nodes on the path. Their main application of the
technique is filtering compromised messages before they actually reach a sink.
6.9 Summary
In this chapter we have presented a family of protocols for communication integrity
protection. The protocols are especially suitable for the use in wireless
sensor networks as they do not rely on extensive end-to-end security relationships.
Instead, local security relationships between k-hop neighbours (with a
small k) and interleavings of authentication paths provide a security level that
approximates that of end-to-end security schemes. The security level can be
further improved by introducing a small number of long-range security relationships.
We have shown the security performance of these protocols through