blockchain

From what i know, blockchain database isn’t stored in any single location, meaning the records it keeps are truly public and easily verifiable. No centralized version of this information exists for a hacker to corrupt. Hosted by millions of computers simultaneously, its data is accessible to anyone on the internet. So my question is can we store blockchain in for example sql? or it can only be stored in a database that works on its own? Currently decentralized blockchain applications have few options to store data. Decentralized storage options are: Storing everything in blockchain itself Peer

I am able to invoke my chaincode from docker cli successfully (fabric-shim). i ran enrollAdmin.js and registerUser.js sucessfully, but when i try to run invoke.js or query.js, i get Error: 2 UNKNOWN: access denied: channel [mychannel] creator org [Org1MSP] . Though there are limited information shows above, the peer log give the essential hint about the problem: WARN 044 channel [mychannel]: MSP error: the supplied identity is not valid: x509: certificate signed by unknown authority (possibly because of "x509: ECDSA verification failure" while trying to verify candidate authority certificate

I came across Hyperledger fabric client which has methods/functions to authenticate new members into blockchain network. But I am not sure how I can authenticate new users into a channel in blockchain network. Can i use channel configuration(configtx) in hyperledger fabric to invite/register new participants into a channel? Link to channel configuration : http://hyperledger-fabric.readthedocs.io/en/latest/configtx.html#channel-creation you can use fabric-ca. Fabric-ca provides several apis for user management. You may register, revoke, enroll, reenroll users by fabric-ca. And the documents for

how display balance of token through Ethereum RPC? $id = 0; $data = array(); $data['jsonrpc'] = '2.0'; $data['id'] = $id++; $data['method'] = 'eth_call'; $data['params'] = [['from' => '0x0...', 'to' => '0x0...', 'data' => 'contract byte code here 0x0...'], 'latest']; $ch = curl_init(); ... Return: {"jsonrpc":"2.0","id":0,"result":"0x"} What to do next? Call contract method balanceOf? How to do that? Kris Roofe To get token balance with eth_call you need to and data parameter. to is contract address, here we need to generate the data parameter. As the doc eth_call says, data: DATA - (optional)

I am creating a blockchain app in Hyperledger that performs a bidding process for a manufacturing company. The bidding process involves 4 suppliers (Supplier A to Supplier D). The one with the lowest bid wins. I am able to create the chaincode for this. However, since it is a blockchain, the suppliers can see each other's bid (e.g., by simply looking at the contents of the blocks). In addition, the non-winning suppliers will know who actually won the bidding process. I want to enforce the following privacy rules in the blockchain: a. the bid of a particular supplier should be viewable only by

In Hyperledger-fabric blockchain, is there a limit to the number of nodes participating in a network? If yes, how many nodes can be in a network? To get the complete functionality of blockchain(consensus mechanism, hyperledger fabric uses PBFT consensus which means it will accept any transaction to be valid if more than 66% of the nodes are up and running. In short more than 66% of nodes must be up and must validate the order to requests in Hyperledger farbic. Both the Starter Developer plan and the High Security Business Network plan enable you to test the Practical Byzantine Fault Tolerance