Create Blockchain Application Enablement Timestamp Service

Once on the SAP Cloud Platform Service Marketplace, locate and open the Blockchain Application Enablement service by clicking the relevant service tile.

Once in the Blockchain Application Enablement service, you will see a service description and the available plans.

Click the Instances tab on the side menu, opening an overview of available instances in your subaccount:

Once on your instances overview, click New Instance to open the service instance wizard:

Select ‘blockchain-timestamp’ as the service plan type and click Next.

Enter the service key details of your chosen blockchain technology in the Specify Parameters field. Example service keys for Hyperledger Fabric, MultiChain, and Quorum are provided here.

Hyperledger Fabric

Use the service key associated with your Hyperledger Fabric development node:

{
	"documentation": "https://help.sap.com/viewer/p/BLOCKCHAIN_APPLICATION_ENABLEMENT",
	"type": "hyperledger-fabric",
	"channelId": "",
	"serviceUrl": "",
	"oAuth": {
	  "clientId": "",
	  "clientSecret": "",
	  "url": ""
	}
}

MultiChain

You must use the service key of your MultiChain service instance. Optionally you can specify the name of a MultiChain stream, that must previously be created.

{
	"documentation": "https://help.sap.com/viewer/p/BLOCKCHAIN_APPLICATION_ENABLEMENT",
	"type": "multichain",
	"stream": "",
	"api_key": "",
	"url": ""
}

Quorum

You must use a service key of your Quorum node instance. In addition you must specify the password of the Quorum account.

{
	"documentation": "https://help.sap.com/viewer/p/BLOCKCHAIN_APPLICATION_ENABLEMENT",
	"type": "quorum",
	"address": "",
	"rpc": "",
	"password": ""
}

Enter an Instance Name and then click Finish.

Your blockchain timestamp service is now created and displayed on the overview of available service instances.

The timestamp service can be used for scenarios in which object states require the verification of a timestamp.

This service contains two APIs that can be used as microservices from other SAP Cloud Platform based applications:

For more API information about this service, see: SAP API Hub - Timestamp

Calls to the APIs themselves require an OAuth access token, that can be obtained using the corresponding URL and credentials (clientId and clientSecret) securely stored in the service key:

{
	"serviceUrl": "https://blockchain-service.cfapps.eu10.hana.ondemand.com/blockchain/timestamp/api/v1/",
	"authentication": {
		"url": "https://'*****.authentication.eu10.hana.ondemand.com",
		"clientId": "sb-'*****-4090-a650-0386988b67e0!b1836",
		"clientSecret": "'******yz1VelAg=",
		"identityZone": "******p"
	}
}

The timestamp service does not allow a key to be overwritten. The key itself can be any string between 64 and 255 bytes in length. We recommend that a well-known hash algorithm with a wide key, for example Secure Hash Algorithm (SHA256) is used to prevent key clashes. In addition, the key can be extended with additional information, such as a document name, the owner, a company name, and so on, all possibly also hashed. The goal is to create one key string that is as unique as possible for the specific blockchain network. Due to the nature of the specific hash algorithm used, there may be a residual possibility of key clashes.