Used for tasks that compute on secret shared data. This is a secure multiparty computation task and is only meaningful when multiple parties execute the same task (tasks that are grouped together to perform the same computation).

The inputs are either secret shares (one share of a value from each party executing a task in this group) or public values (we currently expect that each party running a task in this group inputs the same public data).

The outputs of this task are secret shared where each party executing a task in this group gets a share of the output as a result.

1…n data objects (shares, data), shares from SSSharing tasks or SSComputation task groups

group (with SSComputation tasks)

input script

1 data object (share)

Restriction: task must have at least one input and exactly one output data objects
Error: at least 1 input and exactly 1 output are required

Restriction: “groupId” property must exist under stereotype details object - group must have been selected and saved and “groupId” information must not have been deleted from model’s file
Error: groupId is undefined

Restriction: “inputScript” property must exist under stereotype details object - “inputScript” can be empty, but must not have been deleted from model’s file
Error: inputScript is undefined

Restriction: “inputs” property must exist under stereotype details object - “inputs” information must not have been deleted from model’s file
Error: inputs are undefined

Restriction: all names of input data objects must be different
Error: all input function shares must be different

Restriction: all input data objects fixed (by their ids) in “inputs” property (for all group tasks) must exist also on model
Error: one or more shares (data objects) corresponding to the same input of the group are missing

Restriction: all input data objects corresponding to the same input must be outputs of SSSharing tasks or SSComputation task groups and they must be all from the same stereotype group
Error: all shares corresponding to the same input must originate from the same task with SSSharing stereotype or from the same group of tasks with SSComputation stereotypes

Restriction: all names of input data objects corresponding to the same input must be different
Error: all shares corresponding to the same input must be different

Restriction: there must be at least two tasks in the same stereotype group
Error: group must have at least 2 members

Restriction: the number of members in stereotype group must be greater than or equal to the number on computation parties of each SSSharing tasks
Error: the number of members in SSComputation group is not correct (it should be equal to or greater than the number of computation parties of each task with SSSharing stereotype)

Restriction: all group tasks from the same stereotype group must be on different lanes
Error: each group task must be on separate lane

Restriction: any task from the stereotype group must not be in the incoming or outgoing path of another task from the same stereotype group
Error: all group tasks must be parallel

Restriction: all tasks from the stereotype group must have the same number of input and output data objects
Error: each group task must have the same number of inputs and outputs

Restriction: all tasks from different stereotype groups must be in the same order on each lane - ordered lists of stereotype groups must match for each lane
Warning: all group tasks are possibly not parallel

Restriction: all tasks from the same stereotype group that have common Exclusive Gateway elements in their paths (all tasks have the same exclusive gateway in their paths) must exist in all paths that start from these common exclusive gateways
Warning: group task is possibly not accessible to the rest of the group

Restriction: there must be at least one Start Event element on the model (to run parallelism checks)
Warning: Start Event element is missing