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[Coef]

Well I still haven't got the answer to my question: I'm using multibit and I want the Public Key (It's different than address) of my address, how do I get it? I don't want to know how a public key is calculated, I don't wanna read a dozen pages of math, I just want to know how to get it, period.

First get the private key and then do the conversion to public key with openssl.
http://stackoverflow.com/questions/20086121/convert-ecdsa-private-hex-key-to-public-key

[kuverty]

Well I still haven't got the answer to my question: I'm using multibit and I want the Public Key (It's different than address) of my address, how do I get it? I don't want to know how a public key is calculated, I don't wanna read a dozen pages of math, I just want to know how to get it, period.

It is not that simple, I don't think you can see it from the wallet as it is. I do not use Multibit, though. One thing to note right away is that your address is generated using a cryptographic digest (hash) of your public key, so there is no way you can go back. It is not possible to compute the public key using your public bitcoin adress.

You will need to use your private key to calculate that, there are some tools for this luckily and the easiest method I can think of is going to https://www.bitaddress.org and choosing "Wallet details". There you can input your private key in pretty much any format it happens to be in and it will calculate for you the public key, either in the 65-byte uncompressed format or the 33-byte compressed format, whichever you need. As far as I remember, the page also works offline so you can do that for security and you should, too.

To see yout private key, export your private key to a file in Multibit and open the file in your favourite text editor.
Can I ask, what do you plan using your public key for?

[devthedev]

Well I still haven't got the answer to my question: I'm using multibit and I want the Public Key (It's different than address) of my address, how do I get it? I don't want to know how a public key is calculated, I don't wanna read a dozen pages of math, I just want to know how to get it, period.

Unfortunately, I don't think there is an easy way to find a public key from MultiBit right now.

Thanks Kuverty.

[chaosPT]

Welcome new users!
I've been in the community for a while and have a immerse knowledge of Crypto and related topics.

Feel free to ask me any questions you have about the Bitcoin Protocol, Mining, Legalities, Wallets, etc.
I'll try to answer each and every question posted in the thread!

Looking forward to answering your questions!

~DTD

Tips are appreciated (: 19KsCidkLcNSXWhyQNnV7UfzqyqiSB2oju

EDIT: For every 50 questions asked I'll be giving away a free Woodwallet to a random user who's asked a question or helped others in the thread!

Is there woodcoin since you have wood wallet ?

[JohnFromWIT]

Bump you up.
What does the the block header look like before and after hashing?

[byt411]

Welcome new users!
I've been in the community for a while and have a immerse knowledge of Crypto and related topics.

Feel free to ask me any questions you have about the Bitcoin Protocol, Mining, Legalities, Wallets, etc.
I'll try to answer each and every question posted in the thread!

Looking forward to answering your questions!

~DTD

Tips are appreciated (: 19KsCidkLcNSXWhyQNnV7UfzqyqiSB2oju

EDIT: For every 50 questions asked I'll be giving away a free Woodwallet to a random user who's asked a question or helped others in the thread!

Is there woodcoin since you have wood wallet ?

It's a physical wallet, crafted with wood.

Bump you up.
What does the the block header look like before and after hashing?

As far as I understand, a block header is the block hash. So it would look like this after hashing:

Code:

00000000000008a3a41b85b8b29ad444def299fee21793cd8b9e567eab02cd81

And to get that, you need a few crucial pieces of data: The client version, The hash of the previous block, the hash based on all the transactions to be included in the block, the time, the difficulty, and a random 32-bit number.

[devthedev]

Bump you up.
What does the the block header look like before and after hashing?

As far as I understand, a block header is the block hash. So it would look like this after hashing:

Code:

00000000000008a3a41b85b8b29ad444def299fee21793cd8b9e567eab02cd81

And to get that, you need a few crucial pieces of data: The client version, The hash of the previous block, the hash based on all the transactions to be included in the block, the time, the difficulty, and a random 32-bit number.

Hashing it doesn't change it; it tests whether the header meets the target and will be accepted by the network. So various bits could change for each attempt. You could update nonce, timestamp, the Merkle root, or any combination essentially.

[DannyHamilton]

Bump you up.
What does the the block header look like before and after hashing?

The block header is between 81 and 88 bytes of data.

Before every block header in the blockchain is a 4 byte network ID (in the case of bitcoin this will be 0xD9B4BEF9) and 4 bytes used to indicate the length of the block (in bytes).

The actual block header starts with a 4 byte version number.

Next is the 32 byte hash of the previous block (since each block has a reference to a previous block, they form a chain).

After that is the 32 byte merkle root calculated from the list of previously unconfirmed transactions that the block will include.

That is followed by a 4 byte timestamp, and 4 bytes indicating the current mining difficulty.

The next 4 bytes are the nonce that the miners increment while trying to solve the block.

Finally there is a variable sized integer (anywhere from 1 to 8 bytes) used to indicate the total number of transactions in the block.

For more information, see here:
https://en.bitcoin.it/wiki/Protocol_specification#Block_Headers

and here:
http://james.lab6.com/2012/01/12/bitcoin-285-bytes-that-changed-the-world/

When a node hashes the block to determine if it is "solved", the result of the hash is a 32 byte number.  That number is checked to see if it satisfies the proper difficulty for the block.

[BitsBitsBits]

Could someone help me with how I could make a "vanity address"? I heard you can have a computer generate it with the letters you want yourself the address to have. But don't really understand how that would be possible to do. And how you would get your private key?

Sorry I'm sort of new here.

[devthedev]

Could someone help me with how I could make a "vanity address"? I heard you can have a computer generate it with the letters you want yourself the address to have. But don't really understand how that would be possible to do. And how you would get your private key?

Sorry I'm sort of new here.

Hey! No problem at all, that's what the thread's for. What operating system are you using?

[DannyHamilton]

Could someone help me with how I could make a "vanity address"? I heard you can have a computer generate it with the letters you want yourself the address to have. But don't really understand how that would be possible to do. And how you would get your private key?

Sorry I'm sort of new here.

They way vanity addresses are generated is to run a program that generates random private keys and then calculates the addresses from the private keys.  If repeats this process as fast as it can comparing each address to what you want it to look like until it finds what you're looking for.

There are a few programs available to do this.  As devthedev said, it would help to know what operating system you are using.

The more letters or numbers that you want to match, the longer it will take until the program finds a matching address.

If you just want to match the first letter of the address (after the 1), you will find a match on average in 1 out of every 58 addresses that you generate.

If you want to match the first two letters, you'll find a match on average 1 out of every 3400 addresses that you generate.

If you want to match the first three letters, you'll find a match on average 1 out of every 195000 addresses that you generate.

If you want to match the first four letters, you'll find a match on average 1 out of every 11.3 million addresses that you generate.

If you want to match the first five letters, you'll find a match on average 1 out of every 660 million addresses that you generate.

If you want to match the first five letters, you'll find a match on average 1 out of every 38 billion addresses that you generate.

As you can see, it quickly gets very difficult (and time consuming) to find an address that matches many letters.

[BillyBobJoe]

If you want to match the first five letters, you'll find a match on average 1 out of every 38 billion addresses that you generate.

As you can see, it quickly gets very difficult (and time consuming) to find an address that matches many letters.

Generally, I understand the numbers, I trust the numbers.

But, isn't this a waste of generating numbers? By that I mean what if everybody who gets involved in BTC started trying to generate a vanity address of more and more first X letters, won't that speed up the possible duplication of numbers in some future life time?

Or would it not really matter because all but one of those numbers, the desired vanity address, ever be used?

Trust the Numbers.....

[dvco]

First of all, thanks for helping out the noobies.

Could you recommend me begginer guides for mining, mainly about buying hardware, at what point the investment is worth it, which hardware to buy, etc. I've been searching for guides, but every one I find seems quite outdated.

[devthedev]

If you want to match the first five letters, you'll find a match on average 1 out of every 38 billion addresses that you generate.

As you can see, it quickly gets very difficult (and time consuming) to find an address that matches many letters.

Generally, I understand the numbers, I trust the numbers.

But, isn't this a waste of generating numbers? By that I mean what if everybody who gets involved in BTC started trying to generate a vanity address of more and more first X letters, won't that speed up the possible duplication of numbers in some future life time?

Or would it not really matter because all but one of those numbers, the desired vanity address, ever be used?

Trust the Numbers.....

Bitcoin addresses consist of an alphanumerical string with a length of up to 34 characters, excluding the capital "O", the capital "I" and the lowercase "l", as well as the number "0". Since there are around 1.4*10^48 possible addresses, the chance that a duplicate is found can be calculated using the birthday problem as 1-exp(-(4*10^17)^2/(2*1.4*10^48)), or approximately 0.000000000005%, which means there's a one in 20000 billion of generating the same public/private key pair.

All in all, you don't have to ever worry about a collision or "duplicate"

[JohnFromWIT]

Bump you up.
What does the the block header look like before and after hashing?

The block header is between 81 and 88 bytes of data.

Before every block header in the blockchain is a 4 byte network ID (in the case of bitcoin this will be 0xD9B4BEF9) and 4 bytes used to indicate the length of the block (in bytes).

The actual block header starts with a 4 byte version number.

Next is the 32 byte hash of the previous block (since each block has a reference to a previous block, they form a chain).

After that is the 32 byte merkle root calculated from the list of previously unconfirmed transactions that the block will include.

That is followed by a 4 byte timestamp, and 4 bytes indicating the current mining difficulty.

The next 4 bytes are the nonce that the miners increment while trying to solve the block.

Finally there is a variable sized integer (anywhere from 1 to 8 bytes) used to indicate the total number of transactions in the block.

For more information, see here:
https://en.bitcoin.it/wiki/Protocol_specification#Block_Headers

and here:
http://james.lab6.com/2012/01/12/bitcoin-285-bytes-that-changed-the-world/

When a node hashes the block to determine if it is "solved", the result of the hash is a 32 byte number.  That number is checked to see if it satisfies the proper difficulty for the block.

http://james.lab6.com/2012/01/12/bitcoin-285-bytes-that-changed-the-world/
This is a very helpful resource, I'd advise any newbie interested in the technical side look at it.
Bit daunting at first, but it's not as bad as it looks. You'll get it quickly.

You first gave it to me a couple days ago and I've gone through it in my spare time.
I understand a lot more because of it, but there are still huge gaps in what I know.
I've tried hashing that original block header but can't seem to get the corresponding hash that's recorded.
I must be missing something.

[devthedev]

First of all, thanks for helping out the noobies.

Could you recommend me begginer guides for mining, mainly about buying hardware, at what point the investment is worth it, which hardware to buy, etc. I've been searching for guides, but every one I find seems quite outdated.

Many guides are outdated because Bitcoin mining is no longer profitable unless you have thousands to invest in buying hardware.
However, our miners are important because they process our transactions. Check out AntMiners, they're pretty decent ASICs. Or, if you want to take the cheaper route, just buy some AMD cards (:

[DannyHamilton]

I've tried hashing that original block header but can't seem to get the corresponding hash that's recorded.
I must be missing something.

There are two very common mistakes.  Make sure you aren't making either of these before you waste a lot of time trying to figure out what else you might be missing.

First common mistake:
SHA-256 is calculated on the header, then SHA-256 is calculated on that result.  If you are only calculating the hash of the header, and not calculating the hash of the hash result, then you aren't going to get the right result.


Second common mistake:
Frequently people will make the mistake of storing the result of the first SHA-256 of the header as a string representation of the hex value. Then try to calculate the second SHA-256 on this string instead of on the actual bytes.  A hex value of A is equivalent to a binary value of 1010, but the hex value of the string "A" (if represented in ASCII) is 01000001.

[meprob]

What could I invest into with $10 or 0.0154btc? I earned this from Primedice.com, if anyone is curious.

[Coef]

What could I invest into with $10 or 0.0154btc? I earned this from Primedice.com, if anyone is curious.

Safest option is to hold it, and wait for the bitcoin price to go up.
You could also buy stocks on Havelock, or invest in bankroll of JD, but please stay away from ponzi.

[JohnFromWIT]

stay away from ponzi.

Fonzie's evil twin.

There are two very common mistakes.  Make sure you aren't making either of these before you waste a lot of time trying to figure out what else you might be missing.

First common mistake:
SHA-256 is calculated on the header, then SHA-256 is calculated on that result.  If you are only calculating the hash of the header, and not calculating the hash of the hash result, then you aren't going to get the right result.


Second common mistake:
Frequently people will make the mistake of storing the result of the first SHA-256 of the header as a string representation of the hex value. Then try to calculate the second SHA-256 on this string instead of on the actual bytes.  A hex value of A is equivalent to a binary value of 1010, but the hex value of the string "A" (if represented in ASCII) is 01000001.

Check and check, still not getting it though.
Don't worry about it though I'll get back to it again.