1. A computer-implemented method of identifying an anomalous product in a supply chain, the method comprising: maintaining a set of anomalous patterns of events of a product in the supply chain; transmitting at least one of the anomalous patterns of events to nodes of the supply chain; receiving messages from nodes that have received the at least one pattern at a third party, wherein the third party is not a node of the supply chain, the messages indicating whether or not the occurrence of an event of the product in the supply chain at the node matches an event in the anomalous pattern of events that has been transmitted to the node, wherein messages indicating that an event at the node matches an event in the anomalous pattern of events are securely encrypted by the node prior to transmission to the third party, wherein the encryption is based on a key that is unknown to the third party; and determining, via at least one processor of the third party, that the product is an anomalous product, wherein the determination is based on the messages from nodes indicating that a sequence of events occurring at one or more nodes matches a sequence of events in the anomalous pattern of events.