Sr

Message Type

From

To

Explanation

Example

1

AVAILABILITY_CHECK

Receiver

Sender

Receiver checks file available at Sender

{"AVAILABILITY_CHECK": {"USER": "A"}}

2

FILE_AVAILABILITY

Sender

Receiver

Sender shares list of file signatures

["File Hash 1", "File Hash 2", "File Hash N"]

3

FILE_INFO_REQUEST

Receiver

Sender

Receiver seeks information of the file by using file signature

{"FILE_INFO_REQUEST":

                {"USER": "A", "FILE_HASH": "File Hash X"}}

4

FILE_INFO

Sender

Receiver

Sender shares requested file signature

{"FILE_INFO":

                {"FILE_HASH": "File Hash X",

                "FILE_NAME": "Image_B.png",

                "FILE_SIZE": 523482}}

5

AVAILABILITY_STATUS

Receiver

Peer

Receiver checks availability of the file at Peer

{"AVAILABILITY_STATUS":

                 {"FILE_HASH": "File Hash X",

                "STATUS": "AVAILABLE",

                "CHALLENGES": ["41-98", "14-29", "12-49"]}}

6

FILE_AVAILABLE

Peer

Receiver

Peer confirms availability.

Adds challenges to confirm possession of the file at the sender.

{"FILE_AVAILABLE": {"FILE_HASH": "File Hash X"}}

7

FWD_CHALLENGES

Receiver

Sender

Receiver forwards challenges to the Sender

{"FWD_CHALLENGES":

                {"FILE_HASH": "File Hash X",

                "CHALLENGES": ["41-98", "14-29", "12-49"]}

}

8

RESPONSE

Sender

Receiver

Sender calculates and shares the responses to Receiver

{"RESPONSE":

                 {"FILE_HASH": "File Hash X",

                "RESOLVED_CHALLENGES": {

                                "41-98": "Response 1",

                                "14-29": "Response 2",

                                "12-49": "Response 3"}}}

9

FWD_RESPONSE

Receiver

Peer

Receiver forwards responses to Peer

{"FWD_RESPONSE":

                {"FILE_HASH": "File Hash X",

                "RESOLVED_CHALLENGES": {

                                "41-98": "Response 1",

                                "14-29": "Response 2",

                                "12-49": "Response 3"}}}

10

PEER_DECISION

Peer

Receiver

Peer checks validity of responses. Notifies the Receiver.

{"PEER_DECISION":

                 {"FILE_HASH": "File Hash X",

                "DECISION": "POSITIVE"}}

11

LOCAL_SHARE

Receiver

Peer

Receiver request file transfer after positive decision.

{"LOCAL_SHARE": {"FILE_HASH": "File Hash X"}}

12

SUCCESSFUL_DELIVERY

Receiver

Sender

Receiver notifies Sender about successful file receiving from the Peer.

{"SUCCESSFUL_DELIVERY": {"FILE_HASH": "File Hash X"}}

13

SEND_FILE

Receiver

Sender

Receiver request Sender to transfer after Peers are not able to share.

{"SEND_FILE": {"FILE_HASH": "File Hash N"}}