This is a task for decrypting data that has previously been encrypted with public key encryption.

It takes as an input the ciphertext and the private key and as an output gives the plaintext (assuming that the right key has been used).

2 data objects (private key, ciphertext) from PKEncrypt or PKComputation task

1 data object (data)

Restriction: task must have at exactly two input and one output data objects
Error: exactly 2 inputs and 1 output are required

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

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

Restriction: input data object fixed (by its id) in “ciphertext” property must exist also on model
Error: ciphertext object is missing

Restriction: input data object fixed (by its id) in “key” property must exist also on model
Error: key object is missing

Restriction: ciphertext and key objects must be different data objects - they must have different ids
Error: ciphertext and key must be different objects

Restriction: key data object must have PKPrivate stereotype
Error: key object must have PKPrivate stereotype

Restriction: there must exist a correct key corresponding to the ciphertext - input data object selected as key must be an input object “key” from PKEncrypt task or one of the input objects from PKComputation task selected as “Encrypted” - it must have the same name as input object “key” from PKEncrypt task or as one of the input objects of PKComputation task selected as “Encrypted”
Error: ciphertext is encrypted with wrong encryption method or is not encrypted

Restriction: input data object selected as key must be from the same PKPublic-PKPrivate pair (group) as all other input “encryption key” objects from PKEncrypt tasks
Error: all keys must be from the same PKPublic-PKPrivate key pair