A Privacy Preserving Approach to Collaborative Systemic Risk Identification: The Use-Case of Supply Chain Networks

Table 3

The artifact’s sequences [27].

Step	Executor	Description
		Initialization
1	ISA	Identifies the number of players, , in the network.
2	ISA	Assigns each participating company a (without knowing the real identities of the firms).
3	ISA	Shares the number of players, , with all players in the network and notifies the players to initialize.
4	Player	Each player initializes a new object of class Player and informs ISA.
5	ISA	Notifies all players that the players’ objects exist and they are available to execute the methods.
		Decentral calculation of the shortest paths and path forming players
6	Player	Each player executes the calculateSecureShortestPath() method for itself as the source player and all given targets in the network.
7	Player	Each player executes the calculateNumberOfShortestPaths() method to decentrally set the values of for each given target .
8	Player	Each player executes the determinePlayersOnShortestPaths() method to decentrally calculate the values of for itself as source player and each given target . By termination of the method for all given targets, the player informs ISA.
		Synchronization
9	ISA	ISA informs every player in the network that the determinePlayersOnShortestPaths() is terminated when it receives the notification of termination from all players. This implies that the variables to calculate the BC are available.
		Calculation of the BC
10	ISA	ISA coordinates players for execution of the calculateSecureBetweenness() method. With termination of the method for all players in the network, all firms have their own BCs as well as the BC of all players in the network.