Cryptocurrency Expert

Restore from 24 words seed I have used bitcoinj for createting wallet. I made some changes and try to generate 24 words seed instead of 12 words seed. When I try to restore from 24 words seed, at that time I am using 3 method as mentioned in bitcoinj documentation. Fast catchup. Checkpointing. Bloom filtering. According to documentation, by using these methods you can easily decrease restore time. But it takes maximum 20 to 25 minutes to complete restore. Please help me who knows this process. https://ift.tt/2v84FFE

This California Property Was Sold On Blockchain Without Using Banks PALO ALTO, California - Propy, the global real estate store with a decentralized title registry, announced the successful execution of a historic real estate deal on the Blockchain in the State of California. With Propy’s Transaction Platform, every step of the deal was executed via Ethereum smart contracts, making this the first comprehensive blockchain-recorded property deal in the state of California and only the second in the world. https://ift.tt/2JVl5Xs

Who set the rules for validating a block in blockchain? Who set the rules for validating a block in blockchain? The rules can be set the creator of the blockchain network. There might be some rules on the application that uses the blockchain network. Is it true? How does the rules setting works, how does validation work. https://ift.tt/2NMGELY

Can't specify rpcport for testnet Was there a recent change where it is no longer possible to specify rpcport? I noticed these two warnings: Warning: Config setting for -addnode only applied on test network when in [test] section. Warning: Config setting for -rpcport only applied on test network when in [test] section. After trying adding a [test] section I got very mixed results as some times it disregarded all options and in general rpcport was still not set. I could not find any documentation on how to do this. https://ift.tt/2OkNiu3

How transaction manipulation handles in Blockchain? I'm new to Ethreum and would like to understand few concepts in a detail. After reading about basics of Blockchain, one thing is unclear to me about tx. manipulation. For instance, A has some (i.e: $10) money and A is sending half($5) of it to B. but C manipulate that transaction before going to Blockchain and set $10 instead. Now, A wanted to send only $5, but some how A's account will get empty since miner will check A has enough balance or not. How Blokchain resolves this type of scenario? https://ift.tt/2mPbrg1

PoW 51% attack vs. BFT 1/3 attack? So from what I understand, Bitcoin's PoW is prone to 51% attack, but as a distributed system it is also prone to BFT's 1/3 attack right? I think it's mathematically proven that in a distributed system, if you have more than 1/3 bad nodes collaborate together, then you cannot safely reach a correct consensus no matter what? So for Bitcoin, there are two types of possible attack scenarios, one is if a miner node consistently has more than 51% computing power of the whole network then it can double-spend indefinitely and basically has unlimited cash to spend. The other is if more than 1/3 of the nodes in the whole network are bad guys working together with modified malicious node code then they can potentially stop the correct block being accepted and make it impossible for others to know which is the correct longest chain, thus prevent valid transactions being processed and recorded. So are my understandings correct? https://ift.tt/2A8Fl...

bitcoinrpc.authproxy.JSONRPCException: -26: 16: bad-txns-in-belowout I am getting this exception, when I am using sendrawtransaction. And all I want to do is translate this docs to Python code, and I have searched for a while but both Can anyone shed any light on this error? Bitcore Multisig - bad-txns-in-belowout and Bitcoin core “bad-txns-in-belowout” can't make me clear. and all the exception traceback are list as below: Traceback (most recent call last): File "multisign.py", line 137, in print(ms.go()) File "multisign.py", line 128, in go ret = self.rpc.sendrawtransaction(last_hex) File "/Users/frank/venv/bitcoin/lib/python2.7/site-packages/bitcoinrpc/authproxy.py", line 141, in call raise JSONRPCException(response['error']) bitcoinrpc.authproxy.JSONRPCException: -26: 16: bad-txns-in-belowout Whole my python code as following: import json import binascii from pprint import pprint from bitcoinrpc.authproxy import AuthServiceProxy,...