transactions – Can a trading platform not provide TxID?

I am very new to crypto sphere and I would very much appreciate some expertise knowledge
I’ll try to only include what is relevant information and get straight to the point.

Recently, I have transferred some USDT from a platfrom called Lemoncoin, (
I have binded the address of currency withdrawal with my Huobi account and have double, triple checked the address to be identical with deposit address for USDT of my Huobi account. The chain type was ERC20.

Upon withdrawal from Lemoncoin, it sent me a short message on the bottom of the screen that it will arrive after 12 confirmation, which disappeared on its own within about 1 second. Other than that, there has been absolutely no signs of proof for my withdrawal from this platform and there seems to be no way for me to access a TxID for this transfer.

Is it possible that I have been scammed? Or am I missing something?

transactions – Why is there “Change” in Bitcoins?

And if so, why don’t you just send 0.4 BTC in the beginning?

Bitcoin was designed to allow single-in multi-out or multi-in multi-out payments. In Ethereum, only one address fills the whole “to” field of transactions. (This doesn’t apply to contracts. Does that mean, in Ethereum, users are 2nd class citizens?)

If you were Satoshi and you were to allow transactions with multiple inputs, how would you design transactions so that a change output is not need? I honestly don’t know. Plus, currently “in” fields of transactions reference txid:vout where vout 0, 1, 2, … refers to an output of the transaction.

Israeli Blockchain Startup Company claims they can undo btc transactions | Proxies-free

Let’s face it, to a certain extent we all have a worry in the back of our minds when we withdraw or send crypto, and that worry is that we are unsure of the wallet address. what happens if just one single letter is out on the bitcoin wallet address and your funds are lost? these are all legitimate concerns, and there seems to be a solution to this in development.

Kirobo is a two year old Isreali blockchain start up that announced on Tuesday that there is a way to tackle these problems caused by our own human error in transacting them. Kirobo has developed “Retrievable Transfer,” a route for senders to drop an exchange that is sent to the wrong address. Kirobo gives a unique code to the sender and the beneficiary needs to enter the coordinating secret word so as to get the exchange.

The aim of this creation was to make blockchain transaction as safe and secure as internet banking and to alleviate some of the stress when making a transaction.

I think that such a feature is definitely needed in the crypto world and this will make it much less stressful to send or withdraw your funds. Hopefully more wallets adopt this method as well.


segregated witness – Are P2PKH or P2SH transactions malleable?

BIP66 fixed one source of transaction malleability and segwit, to my understanding, fixed the rest of the sources. Yet, there are still many common types of non-segwit transactions in use, like P2PKH P2SH(PWPKH) P2SH-multisig, are these subject to malleability attacks by a stranger?

I understand that even if someone knows how to do a malleability attack on these transactions, he might choose to answer “no” (or don’t answer) to prevent these attacks. But, on the other hand, if a malleability attack on these common transactions was possible, I believe someone that wants to push for segwit adoption would have already build an app to systematically attack.

merkleblock – How Does the SPV merkle path form of multiple transactions in Merkle block looks like?

While I’m studying about the Bitcoin, I’ve wondered how many merkle paths should be contained in merkle block.

From the point of view of Merkle path, it is generated as the form of containing hashes of counterpart stepping up from bottom to top.

For example, if I have 4 transactions(let me use tx1, tx2, tx3, and tx4) in a block, then the hashes of them(h1, h2, h3, and h4) will be located at the bottom as the leaves. The parents of them will be (h12 and h34), after all, the merkle roots will be (h1234). So, if a SPV node want to verify that the tx2 is in the block, the full node can offer h1, h34 as a merkle path (as well as block header), so that they can prove as the step of hashing will lead them to the merkle roots which is contained in block header.

However, If I requests to verify multiple transactions in a block (e.g. using Bloom filter), then what would be contained into the merkle block (which contains merkle path and block header)?

Does they have ultiple merkle paths for each transactions which are interested in, so that the transactions can be verified respectively? or adapted merkle path to be included which encompass all transactions related? (e.g. if we want to verify tx1, tx3 then generating h2, h3; though this exmample seems not to be guaranteed to show the order of transactions)

innodb – MySQL Code implementation of locking and transactions

I am trying to understand the internals of how MySql (using InnoDB) implements locking and transactions in code. I understand the different types and concepts of locks and transactions, but I really want to deep dive into understanding how MySQL internally implements in code. I tried going through the documentation and MySQL open source code, but could not find a good starting point. Google was no help either. All search results were talking about the different types of locks, but not how they are implemented actually. Any help here?