1. A method for identifying potentially malicious network elements within a network, wherein the network comprises a plurality of domains administrated by different operators, the method comprising: receiving, by a network device of the network, information, encrypted by private keys using a cyclic group, from the different operators qualifying sets of one or more network elements as being potentially malicious, wherein the private keys are distributed to the different operators for encryption of the information, and wherein each of the different operators, or a subset of the different operators, operates a separate network device and receives information from other operators; computing, by the network device, based on the information received from the different operators, a set intersection between the sets of one or more network elements qualified as potentially malicious by the different operators and identifying a network element that appears in all the sets of one or more network elements qualified as potentially malicious by the different operators or in at least a predefined number of the sets of one or more network elements qualified as potentially malicious by the different operators; and providing, by the network device, in response to the computing, a notification to the different operators indicating that the identified network element is potentially malicious.