Hacked bitcoin account.

I believe that my account was hacked: a “send” transaction occurred on my account an hour ago and I lost $62 without my raising any transaction. The transaction is still unconfirmed, how do reverse it and get my money back ? Standing by.
Recipient address-https://blockchain.info/address/18VhGJQgvYVpGLfZPJ1wu85JDAJ8UU6A62
Transaction hash code – https://blockchain.info/tx/ae97308ffd3e460ec4d928d5309479351220b30811d7e02f2a571e23d38e48d2

Once more, I did not make this transaction,and $62 disappeared from my account. Please help.

What is an obfuscation key?

This message appears in my debug.log:

2017-01-21 00:16:42 Opened LevelDB successfully
2017-01-21 00:16:42 Using obfuscation key for /home/<username>/.bitcoin/blocks/index: 0000000000000000

As does this:

2017-01-21 00:16:42 Opened LevelDB successfully
2017-01-21 00:16:42 Using obfuscation key for /home/<username>/.bitcoin/chainstate: <removed>

What is an obfuscation key used for?

How do you hash data for mining?

I was examining the block hashing algorithm and I tried to hash some blocks with my c++ sha256 to check results.

The hashes were wrong all the time so I thought I couldn’t build the block header properly but then I took the data from wiki https://en.bitcoin.it/wiki/Block_hashing_algorithm and concatenated the values from the example and the result is still wrong (I tried it also in online sha-256 calculator so the function is ok).

Of course I must be missing something like coding but if I understand it right, sha is a function where you give a message and it takes the ascii codes of the message and does the math operations on these codes. But how can I pass a block header as a string? Or do I have to find an implementation of sha that interpretes the input differently?

I’m sorry, I know it’s a noob question but this doesn’t seem so obvious to me.

Edit:

The code is quite complex, but what I have at this moment is basically a made up block header that I packed in a string and for the example from the wiki page I mentioned above the string looks like

0100000081cd02ab7e569e8bcd9317e2fe99f2de44d49ab2b8851ba4a308000000000000e320b6c2
fffc8d750423db8b1eb942ae710e951ed797f7affc8892b0f1fc122bc7f5d74df2b9441a42a14695

I also have a sha function that takes a string as an input so the hash should be

1dbd981fe6985776b644b173a4d0385ddc1aa2a829688d1e0000000000000000

but it’s

cf5397ae292d5d37a0df81aa7f89f9fc7e1c43329e441ce2294f0a72e542c7d9

I also checked it on http://www.xorbin.com/tools/sha256-hash-calculator so I think the code is ok but I must just be missing something here.

How to get sending address of MultiSig transaction?

Example hash of transaction: 70c15eb4cc3890960dbe1ae0cf13eedaeaef04d8e4820398fb4e991b23528f03
BlockExplorer shows only 1st address of two. One address is sending address and second is signing address? or two addresses are signing addresses and no sending address? If is second case, how resolve sending address?

Blockchain use in Record Management

From my understanding of blockchain, I feel the main use of blockchain is to do something in a decentralised way as compared to the traditional centralised way which involves a middle man. Usually, the centralised way is a much simpler way, but use of a more complicated way (blockchain) becomes justified because you are able to decentralise.it.

However, I see a lot of companies which are currently the central party trying to get into Blockchains. For e.g. banks etc. I am not sure what advantage there is here.

For example, take a look at this – ironmountain.com – What-is-blockchain-and-why-should-records-management-professionals-care

In my opinion, regular PKI is best suited for this. A user signs his document with his private key & then submits it to Iron Mountain. This will ensure integrity. So what advantage is it to either Iron Mountain or the user if Blockchain is adopted in this case.

It also seems as if Blockchain is getting forced into places where it’s not necessarily the best solution.

Or am I wrong?