A public key is the half of the public/private keypair that is publicized. Anyone can check that a signature is correct, but they can't generate the signature themselves.

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Is it possible to discover the set of bitcoin addresses from a public key?

I'm trying to find the set of bitcoin addresses from a public key associated with a user just to analyse this user transaction. Is there any way to derive/find all the addresses that have been ...
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42 views

How many unique public keys have been published to the block chain?

There have been estimates of the number of published addresses. For example: https://blockchain.info/charts/n-unique-addresses (this chart seems to be underestimating the address count) However, ...
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40 views

Extract all public keys from blockchain [duplicate]

I want to extract all public keys from the blockchain. Those will probably mostly be keys that have been used to sign transactions. How would I do this?
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97 views

All Bitcoin Public Keys with non-zero balance

I want to get a database or otherwise retrieve a set off all bitcoin public keys (not addresses) that have non zero balances. What would be the easiest way to do that? Is there an API that could do ...
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58 views

Can I verify a sub public key came from it's parent public key in a HD wallet without involving any private keys?

I know I can sign a piece of text using a bitcoin private key to prove control over a public address but are there any operations I can perform to know if a public key submitted to me was derived from ...
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59 views

ripemd160(sha256(publickey)) - Where am I going wrong?

(Note: I'm using http://www.royalforkblog.com/2014/08/11/graphical-address-generator/ (use "bitcoin" as the phrase for generating the private key) I'm trying to take the first step in going from a ...
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1answer
71 views

What version byte will produce a Base58 encoding starting with X?

What is the Value of X in Base58? The Problem is when I referred to this table: https://en.bitcoin.it/wiki/Base58Check_encoding I in the end come up with D when I used 30, but I want X, so what will ...
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137 views

Can one wallet send/receive bitcoins from/to multiple sources simultaneously?

Let's say for example I put my public bitcoin address on a website for donations and multiple people for around the world deposit bitcoins simultaneously to that same wallet: Will all deposit ...
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72 views

How can transactions be verified without the private key?

Trying to get my head around her royal Bitcoin here... I understand that blocks of transactions are broadcast to the network, and that miners verify that the BC is 'spendable' by trawling the ...
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1k views

Can private keys remain offline for their entire life?

I am new to Bitcoin and this question is based on 3 assumptions that may be incorrect. Assumption 1: If I understand correctly, the Bitcoin address is generated algorithmically independent of the ...
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1answer
220 views

Create addresses in bulk; and check balance

I am new to Bitcoin; our company wants to use bitcoin for payments. We need to create a address for each transaction. so we need to create many public address. First, I need to generate many public ...
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163 views

How safe is bitcoin with regard to a random address generation attack?

Imagine an attacker implementing something like the following pseudocode on the fastest ASIC farm money can buy: attack(blockchain, my_address) addresses = ...
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208 views

two people with same PUBLIC address, how will people/network know how to deliver bitcoin

I understand that a bitcoin address is a combination or more than one kind of encryption and entropy, and I also understand how improbable it is that the same address will get generated at the same ...
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118 views

Where can I find a C or C++ implementation of converting bitcoin privatekey to bitcoin public key and bitcoin address?

There are versions in python and some such things, but I need a C version (or at least C++). I do have the sha256, RMD160 in C already, and those functions are called. Thank you.
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Other ways to determine the validity of a public key

Public key 3, 4 fits the equation of y^2 = x^2 + 7 Yet this comes up as an "invalid public key". How is that invalid? Sure, it deviates extremely from other numbers, but what other equations are ...
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176 views

How can I get the uncompressed public key from the compressed public key in openssl?

Given a private key, I can get the uncompressed or compressed version of the public key like so. EC_KEY* pKey = EC_KEY_new_by_curve_name(NID_secp256k1); std::vector<unsigned char> ...
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1answer
81 views

Compressed keys default for brainwallet?

I'm somewhat confused re compressed addresses... Assuming I were to make a brainwallet using "correct horse battery staple" as my passphrase gives 1JwSSubhmg6iPtRjtyqhUYYH7bZg3Lfy1T (uncompressed ...
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632 views

How can I convert a bitcoin public key to a bitcoin address?

How can I convert a bitcoin public key to a bitcoin address? Note: I am using PHP. Is there an existing bitcoin API or PHP-API to do that converting ?
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1answer
109 views

Modular Inverse for ECDSA in C++

I've seen several variations on "modular inverse" but I can't seem to identify the proper way of utilizing it for C++. I'm not sure how this python code translates into c++: def inverse(x, p): """ ...
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2answers
92 views

Using paper based public/private keys in bitcoin-qt [duplicate]

If I only have a public key string and a private key string written on a sheet of paper. How do I use those in bitcoin-qt? If this can be added to bitcoin-qt, will it eventually show me how much ...
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1answer
88 views

Why does bitcoin use public keys as pseudonyms?

Why does bitcoin use public keys as pseudonyms? Is there any reason for that? What are the advantages of using public key as the pseudonyms? Highly appreciate if someone can give me an answer.
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1answer
78 views

Genenerate address offline, but blockchain knows about my address

I generate new address in client. I hear that blockchain doesn't know about it. Blockchain will know about it when I use this address for transaction. My example: I generate this address(offline): ...
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148 views

Is it possible generate three public key( address ) by only one private key?

I hear that each address has one private key. Is it possible generate three public key address by only one private key?
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353 views

Is a bitcoin wallet address the same as your public key?

The service CoSign shows that to create a multisig wallet you need to provide a Senders Address and Senders Public Key. I thought that they were the same thing. What am I missing here?
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If I accidentally delete an address with funds

If the address is deleted (while using an online provider like CoinJar), does that mean the coins are lost for good? Or all public/private keys are still held by the company and the address deleted ...
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181 views

Are public keys included in signatures?

I can't easily and quickly determine from these wiki pages, 1 and 2, if the public key is included in the signed message. Are public keys included in the signed message, or are they transmitted ...
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293 views

get public key from wallet.dat

Is there a way to get the public key of a given wallet.dat to check the balance in the blockchain to avoid having to install the wallet and read all blocks?
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763 views

How does ScriptPubKey know the public key of an Bitcoin address?

I am currently having a blonde moment. The ScriptPubKey provides a hashed version of the receivers public key. scriptPubKey OP_DUP OP_HASH160 OP_EQUALVERIFY OP_CHECKSIG However, if I give ...
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653 views

What if duplicate wallet addresses are created? [duplicate]

I'm a newbie to Bitcoin, so I apologize if this seems like a "noob" question. So, from what I've read: anyone can create a new Bitcoin wallet. Upon creation, a wallet address is automatically ...
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336 views

If Bitcoin addresses are truely random, then why are some more difficult to generate than others?

In this post TierNolan explains why 'Bitpoin' is much easier to generate than 'bitpoin', and that mainly has to do with the position (first character). But I remember that certain characters (I ...
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2answers
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In ScriptSig, which form of the public key is considered canonical?

In the standard pay-to-pubKeyHash scriptSig, which form of the public key should be used. My understanding is that both the compressed (33 bytes) and the expanded (64 bytes) are both valid. Is there ...
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1answer
122 views

ECIES - When is it bad to sign and encrypt using the same keys?

Suppose I have a public key for a particular user (perhaps extracted when using the new public key recovery format included in P2SH, and BIP32 transactions). Is it OK the same key for both signing ...
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115 views

Why is an invalid pubkey accepted in the blockchain?

while trying to understand the address validation process, I fell upon this block : https://blockchain.info/tx/3d29f43a3278281192943276049c15e5f0d8c7e75d4d99a4cd6693113a948f48 In the outputs, the ...
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94 views

Isn't bribe smearing possible because no payee signature is required?

The Bitcoin protocol does not require the payee to sign for a payment; only the payer signs (the payer signs a hash of the payee and payer's public keys). In other words, a payee signature is not ...
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346 views

Getting Public Key for transaction in electrum

Liberty.me has asked purchasers to all pay into a single address, but then to email the "public key" of the transaction. What is the public key of the transaction? How would you find it in Electrum?
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2k views

How to export public key for an address in bitcoin-qt?

With the probable increase in demand for multi-sig (P2SH) addresses, and since the procedure for creating such addresses requires that each participant provides the uncompressed public key for an ...
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353 views

How does Nextcoin convert 256-bit Curve25519 public keys into ~20 arabic numerals?

Nextcoin seems to convert 256-bit Curve25519 256-bit public keys into "account numbers" that have only arabic numbers and seem to only have a length of 20. How is that done? Examples In the ...
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792 views

Public key from private key generation problem

I met some problems, when I was trying to write function able to create Bitcoin public key from private key. I was using the tutorial: ...
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538 views

Android Bitcoin Wallet - change addresses and key backup

I've had the Android bitcoin walllet for some time. When I installed it I was assigned some public address/key. I have made various transactions in and out of the wallet but as fas as I can telll the ...
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4k views

How are public and private keys related to the wallet?

I understand that all the Bitcoin protocol is based on an asymmetric cryptography. A user gets 2 keys (public and private). How do these keys connect to the Bitcoins? How are the keys are related ...
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92 views

So every private key actually has TWO associated addresses? (ie uncompressed and compressed)

So every private key actually has TWO associated addresses? (ie uncompressed and compressed) Isn't this a MAJOR flaw if uncompressed keys are still used in applications?
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How are “message signatures” verified without having access to the public key?

In the bitcoin-qt client you can sign and verify messages using only the public address. Since the public address is a RIPEMD160 hash how is it possible that I can verify a signature since I do not ...
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1k views

parsing bitcoin input and output addresses from scripts

can someone walk me through the process of combining script inputs and outputs to reveal the base58 encoded input and output addresses. take for example, block 728. this has two raw script inputs: ...
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1answer
151 views

Exhaustive technical explanation of signing & verification

I apologize for such a noobish question and am ashamed that I'm not getting this yet, but I can't seem to put together all of the pieces. I've read every question I can find on the subject, the ...
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2answers
187 views

Is it true that as long as you have the public and private key for a bitcoin address, you are safe?

So i created a public & private key on blockchain.info and printed it out as a paper wallet. Am I safe to say that no one can comprise it unless they physically get a hold of my piece of paper? ...
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1answer
207 views

How do you derive the public key from you random 256-bits integer?

Once I've flipped a fair coin 256 times and have the random 256 bits integer that I'm going to use as my private key, how is the public key derived? I've read: Given a private key, how do you get a ...
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230 views

Removing old public keys

I have an 'Electrum' wallet. I found some old public keys and imported them into it and then sent the bitcoins to an address in the main wallet. Now the transactions are confirmed and there are 0 ...
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297 views

Why are Bitcoin addresses starting with 1s or 1S so rare?

I've generated 10000-50000 key pairs using Chrome Bit Kit app or www.bitaddress.org and have noticed the scarcity of public keys which begin with 1S and/or 1s. Why is this the case?
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Does a wallet containing multiple addresses have a single private key?

Title says it all. Would one private key enable you to recover all the addresses in your wallet? Or does a wallet just contain a series of key-pairs?
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646 views

How many public keys is there?

How many wallets is there in existence(that are unique with bitcoins)? Is there any page with statistics that can give a bigger perspective other than figuring out the data structure of the ...