Photon Monitoring Service

Photon Monitoring Service, as SM, primarily focuses on mobile platforms. As user’s mobile devices will disconnect from the photon,the user may delegate the PMS to submit the balance_proof and unlock the registered transfer to update the channel in time for securing user’s assets.When the other party’s node do evil, you can also Punish the malicious party.:loudspeaker: Photon Monitoring Service Online bulletin

Build and Installation

Build

git clone https://github.com/SmartMeshFoundation/Photon-Monitoring.git
cd cmd/photonmonitoring
go install

Run as Service

Photonmonitoring requires a Photon node to charge the service. The specific Token and the charge can be configured. The Photon node must be running on port 127.0.0.1:5001, otherwise it will not work. an example run script:

photonmonitoring --datadir=.photonmonitoring --eth-rpc-endpoint ws://192.168.124.13:5555  --address="0x292650fee408320D888e06ed89D938294Ea42f99" --keystore-path=/Users/bai/privnet3/keystore  --registry-contract-address 0x7B319fB135811caeED9969E6a97544f74E312A65  --password-file 123 --verbosity 5  --debug   --smt 0x40db17463AD4A00cc824a37d851725aC7eA4E0B6
Parameters:

  • datadir Local data storage path

  • eth-rpc-endpoint Full node (the mainnet/testnet is online)

  • address Third party service address

  • keystore-path Private key path

  • registry-contract-address Contract address (The mainnet/testnet is online)

  • password-file Private key password

  • smt The address of token

How to use Photon Monitoring Service

Well, how to use this PM service ? In-depth Tutorials will be presented below.

Environment Construction

A complete workflow of a Photon Monitoring Service, at least three nodes and a Photon Monitoring Service are required.

Node Names Node Address
pms node 0x6b9e4d89ee3828e7a477ea9aa7b62810260e27e9
Delegated Charge Node 0x69c5621db8093ee9a26cc2e253f929316e6e5b92
Channel Participantalice 0x31ddac67e610c22d19e887fb1937bee3079b56cd
Channel ParticipantBob 0xf0f6e53d6bbb9debf35da6531ec9f1141cd549d5

Photon Monitoring Start

Run script code below to start pms node.

photonmonitoring  --datadir=.photonmonitoring --eth-rpc-endpoint ws://127.0.0.1:5555  --address="0x6b9e4d89ee3828e7a477ea9aa7b62810260e27e9" --keystore-path ~/.ethereum/keystore --registry-contract-address 0x4dc3388E72e45E99061Ec4Fe17Db2ebfe3B4341f  --password-file /home/niexin/niexin/data.txt  --smt  0xc0dfdD7821c762eF38F86225BD45ff4e912fFA20
echo "quit ok"
Default port for Photon Monitoring : 6000

Start-up Delegated Charge Node

Run script below to operate delegated charged node.

echo run photon...
photon --datadir=.photon --api-address=0.0.0.0:5001 --listen-address=127.0.0.1:40011 --address="0x69c5621db8093ee9a26cc2e253f929316e6e5b92" --keystore-path ~/.ethereum/keystore --registry-contract-address 0x4dc3388E72e45E99061Ec4Fe17Db2ebfe3B4341f  --password-file 123  --eth-rpc-endpoint ws://127.0.0.1:5555  --ignore-mediatednode-request   
echo "quit ok"
ignore-mediatednode-request must be added when start delegated charge node, in case it works as a mediated node of photon and make mistakes at fee-charging.

Run Channel Participant Nodes:

Same as Start-up Delegated Charge Node, you can run codes below to achieve that.

Alice: 

echo privnet
echo run photon...
photon --datadir=.photon --api-address=0.0.0.0:5002 --listen-address=127.0.0.1:40002 --address="0x31ddac67e610c22d19e887fb1937bee3079b56cd" --keystore-path ~/.ethereum/keystore --registry-contract-address 0x4dc3388E72e45E99061Ec4Fe17Db2ebfe3B4341f --password-file 123  --eth-rpc-endpoint ws://127.0.0.1:5555  
echo "quit ok"
Bob: 
echo privnet
echo run photon...
photon --datadir=.photon --api-address=0.0.0.0:5003 --listen-address=127.0.0.1:40003 --address="0xf0f6e53d6bbb9debf35da6531ec9f1141cd549d5" --keystore-path ~/.ethereum/keystore  --registry-contract-address 0x4dc3388E72e45E99061Ec4Fe17Db2ebfe3B4341f --password-file 123  --eth-rpc-endpoint ws://127.0.0.1:5555 
echo "quit ok"
Till now, you’ve completed works for environment construction and nodes have been started. Let me take you to next steps to see how they actually work.

Photon Monitoring Showcase

Scenario : There is a payment channel between Alice and Bob. For some specific reasons, in next few days Bob is about to go offline. when Bob is during the offline period, if Alice closes payment channel between Bob, how can Bob update the newest version of BalanceProof of Alice, so that he can ensure his Security of funds.

This is exactly what our Photon Monitoring Service need to do.

When Bob realizes that he’s going to get off from network, he can delegate Photon Monitoring to update BalanceProof . Once Bob does disconnect from Photon,and the PMS monitors that Alice has closed the channel, the PM node will update BalanceProof on behalf of Bob to retrieve the deserved token from the channel.

There are other cases,such as, a channel participant is a fraudulent actor and attempts to steal tokens from this channel. If he unlocks a abandon transfer which he has declared to dispose, then Our Photon provides punish feature to prevent this case to happen and fraudulent actors will be punished. The Photon Monitoring also providespunish function,All assets in the channel of the evil node are transferred to the other node.Latter we will give you an invidual showcase for this.

Normal Delegation, not including punish

1. Alice makes a transfer to Bob

Via API offered below
POST /api/<version>/transfer/<token_address>/target_address

Example Request: POST http://127.0.0.1:5002/api/1/transfers/0xc0dfdD7821c762eF38F86225BD45ff4e912fFA20/0x31DdaC67e610c22d19E887fB1937BEE3079B56Cd

PAYLOAD

{
    "amount":200,
    "fee":0,
    "is_direct":false
}

2. Bob queries delegation info which need to submit to Photon Monitoring Node

Via API offered below GET: /api/<version>/thirdparty/<channel_address>/<thirdparty_address> Example Request :
GET http://127.0.0.1:5003/api/1/thirdparty/0x2f6418b01422de6cc84fd52e4378fc4449436aeadf69dd543e79e87ee38b6dc8/0x6B9E4D89EE3828e7a477eA9AA7B62810260e27E9

Example Response: 

{
    "channel_identifier": "0x2f6418b01422de6cc84fd52e4378fc4449436aeadf69dd543e79e87ee38b6dc8",
    "open_block_number": 4392735,
    "token_address": "0x445b92d89e21bea3510597a12fefa037718017c1",
    "partner_address": "0x31ddac67e610c22d19e887fb1937bee3079b56cd",
    "update_transfer": {
        "nonce": 2,
        "transfer_amount": 200,
        "locksroot": "0x0000000000000000000000000000000000000000000000000000000000000000",
        "extra_hash": "0xb07638a54d4cbbec93d687d840f13c472df2addae79944dfa00aa2b66ec29b1c",
        "closing_signature": "vwA2lAU414nPajnk5s7dXS/8LHzgCXZ/gVt3lbrzbOhbLkbwcmEW3XtZAjN0qqNYOC8F2opBu7N05FLckrQ5kRw=",
        "non_closing_signature": "aJeOYwRShmkXUBdVTUEKoi5HKKElxn3NfcM8zCRGPcdYJPMv/u+tz9gS3vkb6ypGyvfn1yzKOU1vax3C5/vGMRw="
    },
    "unlocks": null,
    "punishes": null
}

3. Photon Monitoring Service queries whether Tokens are sufficient in delegated charge node.

Via API offered below

GET /fee/<delegater_address>

Example Request :

http://127.0.0.1:6000/fee/0xf0f6E53d6bbB9Debf35Da6531eC9f1141cd549d5

Example Response: 

{
    "Available": 0,
    "NeedSmt": 0
}
- Available - available balance - NeedSmt - fees PM node need to pay

If our delegator has no sufficient fund deposited in Delegated charge node, then he needs to make enough deposit, just normal photon transfers. In our case, Bob deposits/transfers 20 tokens into Delegated charge node.

Example Request : POST http://127.0.0.1:5003/api/1/transfers/0xc0dfdD7821c762eF38F86225BD45ff4e912fFA20/0x69C5621db8093ee9a26cc2e253f929316E6E5b92

PAYLOAD 

{
    "amount":20,
    "fee":0,
    "is_direct":false
}
Then Bob check whether there is sufficient fund in delegated charge node : 

{
    "Available": 20,
    "NeedSmt": 0
}

4. Bob submit the proofs of delegation to Photon Monitoring

Via API below : POST: /delegate/<delegater_address>

Example Request :
POST http://127.0.0.1:6000/delegate/0xf0f6E53d6bbB9Debf35Da6531eC9f1141cd549d5

PAYLOAD 

{
    "channel_identifier": "0x2f6418b01422de6cc84fd52e4378fc4449436aeadf69dd543e79e87ee38b6dc8",
    "open_block_number": 4392735,
    "token_address": "0x445b92d89e21bea3510597a12fefa037718017c1",
    "partner_address": "0x31ddac67e610c22d19e887fb1937bee3079b56cd",
    "update_transfer": {
        "nonce": 2,
        "transfer_amount": 200,
        "locksroot": "0x0000000000000000000000000000000000000000000000000000000000000000",
        "extra_hash": "0xb07638a54d4cbbec93d687d840f13c472df2addae79944dfa00aa2b66ec29b1c",
        "closing_signature": "vwA2lAU414nPajnk5s7dXS/8LHzgCXZ/gVt3lbrzbOhbLkbwcmEW3XtZAjN0qqNYOC8F2opBu7N05FLckrQ5kRw=",
        "non_closing_signature": "aJeOYwRShmkXUBdVTUEKoi5HKKElxn3NfcM8zCRGPcdYJPMv/u+tz9gS3vkb6ypGyvfn1yzKOU1vax3C5/vGMRw="
    },
    "unlocks": null,
    "punishes": null
}
Example Response : 

{
    "Status": 3,
    "Error": ""
}
- status = 1 - delegation failure
- status = 2 - delegation success without enough balance
- status = 3 - delegation success with enough balance

5. Bob Goes Offline

Bob gets disconnected from Internet. If Bob has used Photon Mornitoring Service, then he has to disconnect before channel settle, otherwise when Alice attempts to close this payment channel, Bob will automatically submit balance proof on his own, which can lead to failture that Photon Monitoring Service can not submit valid balance proof.

6. Alice Closes the Channel

Alice close the payment channel when Bob offline.

7. Photon Monitoring Service waits till half past settle_timeout, then update BalanceProof on behalf of delegator.

After our delegator disconnected, if Alice has closed the payment channel, SM Service will monitor the closing events and wait half past the settletimeout, then it will update BalanceProof on behalf of the delegator. In this phase, we can query delegation status via API below.

Via API below :
GET /tx/<delegater_address>/<channel_address>

Example Request : GET http://127.0.0.1:6000/tx/0xf0f6E53d6bbB9Debf35Da6531eC9f1141cd549d5/0x2f6418b01422de6cc84fd52e4378fc4449436aeadf69dd543e79e87ee38b6dc8

Example Response : 

{
    "Status": 3,
    "Error": "",
    "Delegate": {
        "Key": "L2QYsBQi3mzIT9UuQ3j8RElDaurfad1UPnnofuOLbcjw9uU9a7ud6/NdplMeyfEUHNVJ1Q==",
        "Address": "0xf0f6e53d6bbb9debf35da6531ec9f1141cd549d5",
        "PartnerAddress": "0x31ddac67e610c22d19e887fb1937bee3079b56cd",
        "ChannelIdentifier": "L2QYsBQi3mzIT9UuQ3j8RElDaurfad1UPnnofuOLbcg=",
        "OpenBlockNumber": 4392735,
        "SettleBlockNumber": 0,
        "TokenAddress": "0x445b92d89e21bea3510597a12fefa037718017c1",
        "Time": "2018-09-20T16:42:40.411800993+08:00",
        "TxTime": "0001-01-01T00:00:00Z",
        "TxBlockNumber": 0,
        "MinBlockNumber": 0,
        "MaxBlockNumber": 0,
        "Status": 0,
        "Error": "",
        "Content": {
            "channel_identifier": "0x2f6418b01422de6cc84fd52e4378fc4449436aeadf69dd543e79e87ee38b6dc8",
            "open_block_number": 4392735,
            "token_address": "0x445b92d89e21bea3510597a12fefa037718017c1",
            "partner_address": "0x31ddac67e610c22d19e887fb1937bee3079b56cd",
            "update_transfer": {
                "nonce": 2,
                "transfer_amount": 200,
                "locksroot": "0x0000000000000000000000000000000000000000000000000000000000000000",
                "extra_hash": "0xb07638a54d4cbbec93d687d840f13c472df2addae79944dfa00aa2b66ec29b1c",
                "closing_signature": "vwA2lAU414nPajnk5s7dXS/8LHzgCXZ/gVt3lbrzbOhbLkbwcmEW3XtZAjN0qqNYOC8F2opBu7N05FLckrQ5kRw=",
                "non_closing_signature": "aJeOYwRShmkXUBdVTUEKoi5HKKElxn3NfcM8zCRGPcdYJPMv/u+tz9gS3vkb6ypGyvfn1yzKOU1vax3C5/vGMRw=",
                "TxStatus": 0,
                "TxError": "",
                "TxHash": "0x0000000000000000000000000000000000000000000000000000000000000000"
            },
            "unlocks": null,
            "punishes": null
        }
    }
}

8.Settle the Channel

Alice settle the channel. Once Bob reconnects, he can verify his token amount on chain so that he makes sure Photon Monitoring Service actually help him update the most recent BalanceProof.

Punish Delegation

PMS provides a penalty mechanism,this feature is provided to prevent fradulent behaviors, like when one participant goes off, his partner tries to steal tokens via updating abandoned lock.

Scenario :

There is a transfer lock that has been claimed abandoned. Now, let’s change the delegator different from above scenario. Alice plans to get off the network, and she has submitted proofs to Photon Monitoring Service, which includes punishdata. Once Alice actually gets disconnected, Bob attempts to unlock the abandoned lock via fraudulent behaviors to steal the assets of Alice. For the reason that Alice has submitted proofs of punish, which has the ability to verify and punish Bob’s fraudulent behaviors. As a consequence, channel assets of Bob will be transferred to Alice.

1. There is an invalid transfer which Alice sent to Bob. Alice wants PMS to submit balanceproof with penalty

An abandoned transfer lock exists in payment channel of Alice and Bob. Alice submits proof of punish to Photon Monitoring Service.
PAYLOAD 

{
    "channel_identifier": "0x2f6418b01422de6cc84fd52e4378fc4449436aeadf69dd543e79e87ee38b6dc8",
    "open_block_number": 4399083,
    "token_address": "0x445b92d89e21bea3510597a12fefa037718017c1",
    "partner_address": "0xf0f6e53d6bbb9debf35da6531ec9f1141cd549d5",
    "update_transfer": {
        "nonce": 0,
        "transfer_amount": null,
        "locksroot": "0x0000000000000000000000000000000000000000000000000000000000000000",
        "extra_hash": "0x0000000000000000000000000000000000000000000000000000000000000000",
        "closing_signature": null,
        "non_closing_signature": null
    },
    "unlocks": null,
    "punishes": [
        {
            "lock_hash": "0x948443120c7e0c16dac5a0f1df1b3a37c9f19746dd6aca3ad4c28ec201be02c2",
            "additional_hash": "0x6518299834b647647ad4b57dc25ec8bd97b8c3ddd17017c8685065f98b3c0331",
            "signature": "6EemZ91/zqNF7s0wWfgGiPcbm69jOBhmHxfuJ3AQl1wb/NEa7XVrh/o+BDedTBnyA7cubQhssEJ4nHUUE58pMBs="
        }
    ]
}

2. Bob attempts to unlock the abandoned lock to steal tokens

Once Alice gets off, Bob takes a trial to operate fraudulent behavior, and attempts to steal channel assets of Alice.

3. Photon Monitoring Service submits proof of punish

When Bob closes payment channel, and unlock the abandoned lock, our Photon Monitoring Service will help Alice submit proof of punish to the public chain, which has the ability to approve that the lock which Bob tries to unlock has been abandoned by Alice. After verification check, Bob will get punished and all his channel assets will be transferred to Alice. This process ensures asset security of Alice.
Note: The penalty does not occur in the unlock period. We reserved a total of 257 blocks after the settletimeout as the penalty decision period. You can see the penalty information in the event view. It is also possible to verify whether the penalty is successful after the channel settled and look up your token amount on the chain.