OCERT Hyperledger

Structure

• src: Source code of our main contribution, including ocert package that implements the protocol described before, and ocert chaincode that is run in Hyperledger Fabric network.
  • ocert: Ocert package that implements ElGamal rerandomization encryption, structure-preserving signature and non-interactive zero knowledge proof system, as well as ocert main scheme.
  • chaincode/ocert.go: The script that run in Hyperledger Fabric network, which is based on ocert_scheme.go. It implements Init and Invoke chaincode functions, and provides functions like GenECert and GenOCert to the client.
• chaincode-docker-devmode: This module relies on the chaincode-docker-devmode example in Hyperledger Fabric tutorial. It starts a docker environment that is used to test a chaincode, including a chaincode container where the ocert chaincode runs and a cli container where a client can interact with ocert chaincode. The docker-compose configuration file is modified so it first builds the images integrating PBC library for chaincode and cli containers before starting up the whole environment. During starting up, ocert package and ocert chaincode are copied into chaincode and cli containers. Once up, the docker environment is ready for running and testing ocert chaincode.
• docker: This module contains two Dockerfiles that are used to build the images mentioned in docker-compose configuration file, one for chaincode container and another for cli container.
• benchmark: This module contains scripts used in evaluation, including one script benchmarkcc.go. It can run in cli container, interact with ocert chaincode and collect data for benchmark.
• data: This module contains three files recording data generated during benchmark. genOCertLog.txt records the total time to generate one ocert; genProofLog.txt records the time to generate a proof of knowledge in one ocert generation; verifyProofLog.txt records the time to verify a proof of knowledge in one ocert generation.
• benchmark-analysis-tool: This module contains the script used to evaluate benchmark date.

Build and Run

To run ocert chaincode, please open three Terminals and navigate to chaincode-docker-devmode in each Terminal

• Terminal 1: Start the network Setup the whole docker environment by

  docker-compose -f docker-compose-simple.yaml up
  

• Terminal 2: Build and start the chaincode First enter chaincode container by

  docker exec -it chaincode bash
  

  Then build ocert chaincode

  cd ocert
  go build ocert.go
  

  Last, start chaincode

  CORE_PEER_ADDRESS=peer:7051 CORE_CHAINCODE_ID_NAME=mycc:0 ./ocert
  

• Terminal 3: Use the chaincode First enter cli container by

  docker exec -it cli bash
  

  Then initialize chaincode

  peer chaincode install -p chaincodedev/chaincode/ocert -n mycc -v 0
  peer chaincode instantiate -n mycc -v 0 -c '{"Args":[]}' -C myc
  

  Now you can play around ocert chaincode. For example, you can get the bilinear group used in the protocol

  peer chaincode query -n mycc -c '{"Args":["sharedParams"]}' -C myc
  

  or the public keys

  peer chaincode query -n mycc -c '{"Args":["get","auditor_pk"]}' -C myc
  peer chaincode query -n mycc -c '{"Args":["get","structure_preserving_vk"]}' -C myc
  peer chaincode query -n mycc -c '{"Args":["get","rsa_pk"]}' -C myc
  

  and definitiely, generate ecert and ocertS

  peer chaincode query -n mycc -c '{"Args":["genECert", arguments_used_by_GenECert]}' -C myc
  peer chaincode query -n mycc -c '{"Args":["genOCert", arguments_used_by_GenOCert]}' -C myc
  

  You should generate arguments_used_by_GenECert and arguments_used_by_GenOCert, and encode them by Bytes() from types.go. Please refer benchmarkcc.go to use these functions. You also need to use the SetBytes() from types.go to decode the result from these functions.