Proof of Existence Part 2 — Creating data stream to store hash of the file and metadata in…

Proof of Existence Part 2 — Creating data stream to store hash of the file and metadata in blockchain network.

Step 1: First we would create a new blockchain named chain1. On the first server, run this command:

multichain-util create chain1

Step 2 : Initialize the blockchain, including mining the genesis block. multichaind chain1 -daemon

Step 3 : Get info of blockchain run command (multichain-cli chain1).

sourabhsethi8888@mutichain-instance-1:~$ multichain-cli chain1

MultiChain Core RPC client build 1.0 alpha 26 protocol 10006


Interactive mode

chain1: getinfo
{"method":"getinfo","params":[],"id":1,"chain_name":"chain1"}

{
"version" : "1.0 alpha 26",
"protocolversion" : 10006,
"chainname" : "chain1",
"description" : "MultiChain chain1",
"protocol" : "multichain",
"port" : 9565,
"setupblocks" : 60,
"nodeaddress" : "chain1@10.142.0.4:9565",
"burnaddress" : "1XXXXXXWZzXXXXXXYBXXXXXXbVXXXXXXWsKJr3",
"incomingpaused" : false,
"miningpaused" : false,
"walletversion" : 60000,
"balance" : 0.00000000,
"walletdbversion" : 2,
"reindex" : false,
"blocks" : 15549,
"timeoffset" : 0,
"connections" : 0,
"proxy" : "",
"difficulty" : 0.00001526,
"testnet" : false,
"keypoololdest" : 1530472920,
"keypoolsize" : 2,
"paytxfee" : 0.00000000,
"relayfee" : 0.00000000,
"errors" : ""
}
chain1:

Step 4: Create stream POE in chain1.

Now let’s create a stream POE, which can be used for general data storage and retrieval.

chain1: create stream poe false
{"method":"create","params":["stream","poe",false],"id":1,"chain_name":"chain1"}

922ce92090a540222ccd2cb9349d7fc34fd83570938b9e500102543189667f95
chain1:

The false means the stream can only be written to by those with explicit permissions. Let’s see its permissions:

chain1: listpermissions poe.*
{"method":"listpermissions","params":["poe.*"],"id":1,"chain_name":"chain1"}

[
{
"address" : "1HGMosmcKEPUnwD2DzNUfQ46HCA9Th4mBZCZEF",
"for" : {
"type" : "stream",
"name" : "poe",
"streamref" : "15591-267-11410"
},
"type" : "admin",
"startblock" : 0,
"endblock" : 4294967295
},
{
"address" : "1HGMosmcKEPUnwD2DzNUfQ46HCA9Th4mBZCZEF",
"for" : {
"type" : "stream",
"name" : "poe",
"streamref" : "15591-267-11410"
},
"type" : "activate",
"startblock" : 0,
"endblock" : 4294967295
},
{
"address" : "1HGMosmcKEPUnwD2DzNUfQ46HCA9Th4mBZCZEF",
"for" : {
"type" : "stream",
"name" : "poe",
"streamref" : "15591-267-11410"
},
"type" : "write",
"startblock" : 0,
"endblock" : 4294967295
}
]
chain1:

subscribe poe

chain1: subscribe poe
{"method":"subscribe","params":["poe"],"id":1,"chain_name":"chain1"}

Step 5: So for now, only the first server has the ability to write to the stream, as well as administrate it. Let’s publish something to it, with key key1:

chain1: publish poe key1 73747265616d2064617461
{"method":"publish","params":["poe","key1","73747265616d2064617461"],"id":1,"chain_name":"chain1"}

744f9a635f6fb34ee9fa58245341d6d9799574c94fa2c5dc960e7961b80d9f81
chain1:

Step 6: Now let’s query the stream’s contents in many different ways.

liststreamitems poe

chain1: liststreamitems poe
{"method":"liststreamitems","params":["poe"],"id":1,"chain_name":"chain1"}

[
{
"publishers" : [
"1HGMosmcKEPUnwD2DzNUfQ46HCA9Th4mBZCZEF"
],
"key" : "key1",
"data" : "922ce92090a540222ccd2cb9349d7fc34fd83570938b9e500102543189667f95",
"confirmations" : 22,
"blocktime" : 1530693688,
"txid" : "525cc31b4de0627f19a9bea627fad933252d8ccecdf7a7a04cbf9a3486686f78"
},
{
"publishers" : [
"1HGMosmcKEPUnwD2DzNUfQ46HCA9Th4mBZCZEF"
],
"key" : "key1",
"data" : "73747265616d2064617461",
"confirmations" : 6,
"blocktime" : 1530693893,
"txid" : "744f9a635f6fb34ee9fa58245341d6d9799574c94fa2c5dc960e7961b80d9f81"
}
]
chain1:chain1: liststreamkeys poe
{"method":"liststreamkeys","params":["poe"],"id":1,"chain_name":"chain1"}

[
{
"key" : "key1",
"items" : 2,
"confirmed" : 2
}
]chain1: liststreampublishers poe
{"method":"liststreampublishers","params":["poe"],"id":1,"chain_name":"chain1"}

[
{
"publisher" : "1HGMosmcKEPUnwD2DzNUfQ46HCA9Th4mBZCZEF",
"items" : 2,
"confirmed" : 2
}
]
chain1:

Conclusion : One would be able to understand the Streams in multichain network to store the data in blockchain.

Proof of Existence Part 2 — Creating data stream to store hash of the file and metadata in… was originally published in Virtue on Medium, where people are continuing the conversation by highlighting and responding to this story.