How can I create a private blockchain with my own transactions? I need to create a transaction where Alice can write a message and send it to Bob, for example: Alice sends a "Hello" message to Bob, to achieve this, Alice creates a transaction and sends all her interconnected blockchain nodes. Each node validates that transaction (with some policy) and if a valid transaction sends the transaction back to all its connected nodes. Then the mining nodes add it to a block and also add that block to the blockchain. To be able to achieve all this procedure I have to modify some code blockchain (a code poorly documented). Would you know if it is feasible to do? Would you know if there is a place that can help me achieve it? Regards!.
Here there is a repository that allows you to add all kinds of data to a blockchain.
If you look at the "Data" field of each block you can add your own transaction in JSON format.