An Adversarial Evaluation of Network Signaling and Control Mechanisms - Information Security and Cryptology-ICISC 2010 - page 263

Ta b l e 1 . Control mechanisms and their labels

Label Control mechanisms

DHT Chord with successor list size of 5 (default).

DHT S-list Extend DHT by adding 2 connections to successor list. Successor list size is set to 7.

HYBR Hybrid mechanism that naıvely integrates 2 additional SN connections to DHT .

This is the hybrid network used from previous evaluations.

HYBR F-table This extends HYBR by integrating 2 additional SN-connections with the finger table.

6.2 Evaluation of Network Coverage

We measured the performance of our proposed modifications in terms of coverage.
To that end, we present our experimental results from the degree dependent attack by
varying its attack rate (0% 30%) for a network of 20,000 participating nodes. The

cluster size for hybrid network was set to 50 to make the effect of SN connections more
pronounced. With larger cluster sizes, thus smaller SN connections, we expect coverage
results similar to that of a DHT network. Table 1 details specific configurations and their
labels used for evaluations. The evaluation results are presented in Figure 4(b).
The last three configurations ( DHT S-list , HYBR , HYBR F-table ) from Table 1 are im-
plemented with the same number (two) of additional connections to the original Chord
DHTs ( DHT ). The result for DHT S-list shows the limited effects of the two additional
success list entries. From Figure 4(b), this improves coverage only by 2

∼

3%. The re-

∼

sult for HYBR shows better coverage (5 6%) than DHT S-list . Although SN connec-

tions replace connections assigned to the successor list, the structural benefits offered
by the SN network are far greater. This is apparent in the HYBR F-table , by harnessing
the reliability benefits of both successor list entries and SN connections, the coverage

∼

180

Super node
Regular node
1% attack
4% attack

DHT
DHT S−list
HYBR
HYBR F−table

100

160

90

140

80

120

70

100 60

50

80

40

60

30

40

20

20

10

0 0

0 0.5 1 1.5 2

x 10 4

5 10 15 20 25 30

Nodes

Attack rate (%)

(a) Distribution of incoming connection (b) Integrations under the degree dependent at-

tack

Fig. 4. (a) enumerates connections for nodes in a hybrid network with cluster size of 50. The dot-
ted and dashed lines show the impact of the degree dependent attack. The attacker choose victims
with number of connection above the lines. (b) presents the coverage for different modifications
and for the degree dependent attack. In X-axis we vary the attack intensity while Y-axis shows
the alert success rate.