How can i switch from BIP32 to BIP44 using bitcoinj

i am working on a wallet that is using BIP32 for creating Accounts, addresses, xpub, public keys, transaction and etc. but now i want to switch from BIP32 to BIP 44. how can i do this using bitcoinj i also study this, but there is nothing related to implementation. All i need to know that how can i implement BIP44 using bitcoinj and what is specific changes i have to do.Do i have to change all the hierarchy, if yes, then how can do this

Transactions for multiple crypto-currency coins in cold storage without downloading full block-chains

I’ve searched on the internet and still unable to understand the usage of cold storage. Actually, I want to buy a few types of low price crypto currency coins and save them in my personal devices or papers. Later I need to send them to some exchanges to sell at higher price. I don’t want to rely on online sites/firm meanwhile before exchange. Neither I want to download blockchains of each currency.

So, how can I efficiently save my coins in my personal captivity? If I use offline wallet generator, how In-ward and Out-ward transactions will be carried out?

anyonecanspend final condition of a script can be spotted just by looking at the script hash, without the redeem data?

Consider the following scenario.

Alice, Carol and Bob create and fund a script with the following rules:
if now, alice pubkey, bob pubkey
else
if now+500 blocks, bob pubkey, carol pubkey
else
if now+1000 blocks, ANYONECANSPEND

The question is if anyone (besides Alice, Bob and Carol who have the redeem script) can tell by looking at the address (script hash) that its final condition is ANYONECANSPEND, and miners for example choose not to include it in a block until the last nLockTime passes and the miner can claim the entire output, not just the fee.

Based on my current understanding, just by looking at a native P2WSH address (hash of script) it tells you nothing about the redeem script, or am I wrong?

Also, can miners learn the final condition if the output is spent at its second nLockTime, like when Bob and Carol try to spend, they must also provide the redeem script, thus allowing miners to see that if they wait 500 more blocks they can claim the entire output, not just the fee, and not include it in a block until then. Thank you.

Bitcoin Speed: 7 Transactions Per Second?

I read somewhere that Bitcoin can only handle 7 transactions per second. This works out to 604,800 transactions per day. Visa currently processes about 1,700 transactions per second (and can handle vastly higher amounts than this). This means that the Bitcoin system can handle less than 1/200 of Visa’s current processing output.

Is this correct? I find it hard to believe that so many people would buy into a system that’s so inefficient / unscalable.

Also, if my assumption is correct, suppose there are (on avg) 700 transactions per second during a given 10 min period (i.e, 70 times the max output rate) does this mean we will need to wait 70 * 10 min for all those transactions to be confirmed? If yes, why can’t some evil actor overwhelm (i.e, postpone) the system by submitting thousands of tiny transactions to the network?

Thanks in advance

How can testnet CashAddr addresses be converted back to the old format?

I noticed on the new update of the Bitcoin Cash wallet (BitcoinABC) (for testnet and not sure for mainnet) that it has a weird beginning and address (e.g. bchtest:qrz89sz3r47ndj60xq68xeus0hx9qwlpkuw5pw01de). Is there any way to convert it back to the old format as there are some places that don’t support this format yet (like one of the BCH testnet faucets)?

LND describegraph and getnetworkinfo RPC response

The LND API documentation is here, but doesn’t contain much information about what the responses to various calls mean. Can anyone explain what these responses are describing?

describegraph[‘edges’]

I understand this to be channel data, but not sure exactly what it’s describing.

  • “time_lock_delta”: 14,
  • “min_htlc”: “0”,
  • “fee_base_msat”: “546000”
  • “fee_rate_milli_msat”: “10”

getnetworkinfo

  • “avg_out_degree”: 2.841628959276018
  • “max_out_degree”: 102

Does the Bech32 address format decrease Bitcoin’s possible address count?

I have wondered how many Bitcoin addresses are possible. When looking around, I stumbled upon this thread on BitcoinTalk:

There are exactly 2^160 possible addresses as long as we keep using
RIPE-MD160.

2^160 is
1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976.

Then I wondered if there are less possible addresses with the Bech32-format, specified by BIP 0173.

Besides, you cannot use uppercase format of characters in your computation, and some numbers as letters, such as i/1 and o/0 characters/numbers are excluded in Bech32 format.

Should that not decrease the possible amount of Bitcoin addresses dramatically, and decrease the security of Bitcoin?

So, I would like to know how many possible Bitcoin addresses there are with Bech32 format. How could I calculate it? What will the total number (plain long number, not the squared one, I’m not good in math) of possibilities be with the restrictions of Bech32 then?

What are the costs of cryptocurrency fraud?

I have heard many claims that transaction volumes can be “faked” for cryptocurrencies, but I am skeptical about how this is possible. I want someone to walk me through the math describing what you need to believe in order to make money by boosting transaction volumes.

1) First, assume a constant velocity of money but a positive transaction cost t. Suppose t is relatively high. Is it possible to make money as a market manipulator? What would these profits be? Is there a point where t prevents you from making money as a manipulator?

2) Second, assume it is possible that coin velocity declines because momentum-driven speculators enter on news that prices rose due to “fake” transaction volumes from the market manipulator. What is the required velocity change as a function of the transaction cost t?

I am not sure whether I understand the math here, but I suspect that coin manipulation is possible. However, there is a point where t exceeds the possible change in coin velocity, which creates a limit to market manipulation.