15-01-2014, 12:30 PM
Robust Correlation of Encrypted Attack Traffic Through Stepping Stones by Flow Watermarking
[attachment=59883]
ABSTRACT:
Network based intruders seldom attack their victims directly from their own computer. Often, they stage their attacks through intermediate “stepping stones” in order to conceal their identity and origin. To identify the source of the attack behind the stepping stone(s), it is necessary to correlate the incoming and outgoing flows or connections of a stepping stone. To resist attempts at correlation, the attacker may encrypt or otherwise manipulate the connection traffic. Timing based correlation approaches have been shown to be quite effective in correlating encrypted connections. However, timing based correlation approaches are subject to timing perturbations that may be deliberately introduced by the attacker at stepping stones.
EXISTING SYSTEM:
i) Existing passive correlation approaches, our active
watermark based correlation does not make any limiting assumptions about the distribution or random process of the original inter-packet timing of the packet flow.
ii) our watermark based correlation can’t achieve arbitrarily close to 100% correlation true positive rate and arbitrarily close to 0% false positive rate at the same time for sufficiently long flows, despite arbitrarily large (but bounded) timing perturbations of any distribution by the attacker
iii) The following problem can’t be rectified by the existing system. There are following
*) While the attacker can add extra delay to any or all packets of an
outgoing flow at the stepping stone, the maximum Delay he or she can introduce is bounded.
*) All packets in the original flow are kept. No packets are
Dropped from or added to the flow by the stepping stone.
*) While the watermarking scheme is public knowledge, the
Watermarking embedding and decoding parameters are secrets
Known only to the watermark embedder and the
Watermark detector(s).
PROPOSED SYSTEM:
i) In this paper we propose a novel watermark-based correlation Scheme that is designed specifically to be robust against timing perturbations.
ii) Unlike most previous timing based correlation approaches, our watermark-based approach is “active” in that it embeds a unique watermark into the encrypted flows by slightly adjusting the timing of selected packets.
iii) The unique watermark that is embedded in the encrypted flow gives us a number of advantages over passive timing based correlation in resisting timing perturbations by the attacker
iv) our watermark based correlation can achieve arbitrarily close to 100% correlation true positive rate and arbitrarily close to 0% false positive rate at the same time for sufficiently long flows, despite arbitrarily large (but bounded) timing perturbations of any distribution by the attacker
v) Experimental results show that our active watermark based correlation performs better and requires fewer packets than existing, passive timing based correlation methods in the presence of random timing perturbations.
[attachment=59883]
ABSTRACT:
Network based intruders seldom attack their victims directly from their own computer. Often, they stage their attacks through intermediate “stepping stones” in order to conceal their identity and origin. To identify the source of the attack behind the stepping stone(s), it is necessary to correlate the incoming and outgoing flows or connections of a stepping stone. To resist attempts at correlation, the attacker may encrypt or otherwise manipulate the connection traffic. Timing based correlation approaches have been shown to be quite effective in correlating encrypted connections. However, timing based correlation approaches are subject to timing perturbations that may be deliberately introduced by the attacker at stepping stones.
EXISTING SYSTEM:
i) Existing passive correlation approaches, our active
watermark based correlation does not make any limiting assumptions about the distribution or random process of the original inter-packet timing of the packet flow.
ii) our watermark based correlation can’t achieve arbitrarily close to 100% correlation true positive rate and arbitrarily close to 0% false positive rate at the same time for sufficiently long flows, despite arbitrarily large (but bounded) timing perturbations of any distribution by the attacker
iii) The following problem can’t be rectified by the existing system. There are following
*) While the attacker can add extra delay to any or all packets of an
outgoing flow at the stepping stone, the maximum Delay he or she can introduce is bounded.
*) All packets in the original flow are kept. No packets are
Dropped from or added to the flow by the stepping stone.
*) While the watermarking scheme is public knowledge, the
Watermarking embedding and decoding parameters are secrets
Known only to the watermark embedder and the
Watermark detector(s).
PROPOSED SYSTEM:
i) In this paper we propose a novel watermark-based correlation Scheme that is designed specifically to be robust against timing perturbations.
ii) Unlike most previous timing based correlation approaches, our watermark-based approach is “active” in that it embeds a unique watermark into the encrypted flows by slightly adjusting the timing of selected packets.
iii) The unique watermark that is embedded in the encrypted flow gives us a number of advantages over passive timing based correlation in resisting timing perturbations by the attacker
iv) our watermark based correlation can achieve arbitrarily close to 100% correlation true positive rate and arbitrarily close to 0% false positive rate at the same time for sufficiently long flows, despite arbitrarily large (but bounded) timing perturbations of any distribution by the attacker
v) Experimental results show that our active watermark based correlation performs better and requires fewer packets than existing, passive timing based correlation methods in the presence of random timing perturbations.