Multipath network traffic distribution methods for reduced detectability
A method of sending a flow of a plurality of data packets across a data network from a source node to a destination node is provided, the data network including a plurality of links between nodes. The method includes: (a) determining a set of weights, the weights corresponding to respective links of the plurality of links, such that obeying the set of weights during data transmission tends to minimize side channel leakage for the flow; and (b) routing packets of the flow along the plurality of links of the data network according to their respective weights. A corresponding apparatus, system, and computer program product are also provided.
1 . A method of sending a flow of a plurality of data packets across a data network from a source node to a destination node, the data network including a plurality of links between nodes, the method comprising:
determining a set of weights associated with minimizing side channel leakage for the flow of the plurality of data packets across the data network from the source node to the destination node, the weights corresponding to respective links of the plurality of links, such that obeying the set of weights during data transmission minimizes the side channel leakage for the flow; and
routing packets of the flow along the plurality of links of the data network according to their respective weights.
2 . The method of claim 1 wherein determining the set of weights such that obeying the set of weights during data transmission tends to minimize side channel leakage includes utilizing a spreading scheme that spreads traffic across a plurality of diverse paths.
3 . The method of claim 2 wherein utilizing the spreading scheme includes minimizing a maximum load per intermediate node of the data network between the source node and the destination node.
4 . The method of claim 2 wherein utilizing the spreading scheme includes applying a quadratic spreading strategy to achieve maximal spreading across all outgoing links at each node.
5 . The method of claim 1 wherein determining the set of weights includes imposing a Quality of Service (QoS) constraint, including ensuring that a sum of products of a respective cost of traversing each link with the weight for that link over all links of the data network does not exceed the QoS constraint.
6 . The method of claim 5 wherein determining the set of weights further includes ensuring that each weight of the set of weights does not exceed a maximum capacity of the corresponding link.
7 . The method of claim 6 wherein the method further comprises sending another flow of another plurality of data packets across the data network from another source node to another destination node by:
determining another set of weights, the other weights of the other set of weights corresponding to respective links of the plurality of links, such that obeying the other set of weights during data transmission tends to minimize side channel leakage for the other flow, including ensuring that, for each link of the plurality of links, a sum of the corresponding weight and corresponding other weight does not exceed the maximum capacity of that link; and
routing packets of the other flow along the plurality of links of the data network according to their respective other weights.
8 . The method of claim 5 wherein determining the set of weights further includes:
for all untrusted links, setting their respective costs to a maximum value; and
for all links that input into or output from any untrusted node, setting their respective costs to a maximum value.
9 . The method of claim 8 wherein determining the set of weights further includes, in response to determining that ensuring that the sum of products of the respective cost of traversing each link with the weight for that link over all links of the data network does not exceed the QoS constraint is impossible, reducing the costs of one or more links having respective costs set to the maximum value.
10 . The method of claim 1 wherein routing packets of the flow along the plurality of links according to their respective weights includes, at each node of the data network except the destination node, stochastically routing packets of the flow to respective links emanating from that node in proportion to the respective weights of each link emanating from that node.
11 . The method of claim 1 wherein each of the plurality of data packets of the flow is encrypted.
12 . A computer program product comprising a non-transitory computer-readable storage medium storing a set of instructions, which, when executed by processing circuitry of a computing device, causes the computing device to:
send a flow of a plurality of data packets across a data network from a source node to a destination node, the data network including a plurality of links between nodes, by:
determining a set of weights associated with minimizing side channel leakage for the flow of the plurality of data packets across the data network from the source node to the destination node, the weights corresponding to respective links of the plurality of links, such that obeying the set of weights during data transmission minimizes the side channel leakage for the flow; and
routing packets of the flow along the plurality of links of the data network according to their respective weights.
13 . The computer program product of claim 12 wherein determining the set of weights such that obeying the set of weights during data transmission tends to minimize side channel leakage includes utilizing a spreading scheme that spreads traffic across a plurality of diverse paths.
14 . The computer program product of claim 13 wherein utilizing the spreading scheme includes minimizing a maximum load per intermediate node of the data network between the source node and the destination node.
15 . The computer program product of claim 13 wherein utilizing the spreading scheme includes applying a quadratic spreading strategy.
16 . The computer program product of claim 12 wherein determining the set of weights includes imposing a Quality of Service (QoS) constraint, including ensuring that a sum of products of a respective cost of traversing each link with the weight for that link over all links of the data network does not exceed the QoS constraint.
17 . A system comprising:
a plurality of computing nodes, including a source node, a destination node, and a plurality of intermediate nodes; and
a network configured to connect the source node to the destination node via links between the plurality of computing nodes;
wherein the source node is configured to determine a set of weights associated with minimizing side channel leakage for a flow of a plurality of data packets across the network to the destination node, the weights corresponding to respective links of the plurality of links, such that obeying the set of weights during data transmission minimizes the side channel leakage for the flow; and
wherein the source node and the plurality of intermediate nodes are configured to route packets of the flow along the plurality of links of the network according to their respective weights.
18 . The system of claim 17 wherein determining the set of weights such that obeying the set of weights during data transmission tends to minimize side channel leakage includes utilizing a spreading scheme that spreads traffic across a plurality of diverse paths.
19 . The system of claim 17 wherein determining the set of weights includes imposing a Quality of Service (QoS) constraint, including ensuring that a sum of products of a respective cost of traversing each link with the weight for that link over all links of the data network does not exceed the QoS constraint.
20 . The system of claim 17 wherein routing packets of the flow along the plurality of links according to their respective weights by a node includes stochastically routing packets of the flow to respective links emanating from that node in proportion to the respective weights of each link emanating from that node.