Questions tagged [public-key]

This tag should be used for questions regarding public keys. A public key is the public half of the public/private keypair. Anyone can use a public key check that a signature is correct, but they can't generate the signature themselves with the public key.

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69
votes
4answers
33k views

What is a compressed Bitcoin key?

The standard Bitcoin client in version 0.6 apparently introduces compressed keys. What are they? Are there any drawbacks to using them? Any incompatibilities with older software? Reductions in ...
29
votes
5answers
17k views

How are public & private keys in an address created?

I understand the high level concept I am more interested specific details. How is a private key generated. How exactly is public key generated, how is address generated from public key.
3
votes
1answer
1k views

Verifying a bitcoin trx on the Unix cmd line with OpenSSL?

I want to use openssl on unixoide systems to verify a transaction. I step on errors, when trying to verify a bitcoin trx’s hash. Here I am working on Mac OSX and OpenSSL (1.0.2a 19 Mar 2015). I know ...
4
votes
2answers
602 views

What would happen if two public keys had the same Base58 hash?

If two different public keys had the same Base 58 hash, what would happen? Could one key spend money in the other account? What would happen to the monies received by the shared base58 hash?
58
votes
6answers
22k views

What is relation between scriptSig and scriptPubKey?

Scenario: A is sending 1 BTC to B. scriptSig appears in the Input Script. scriptSig = <sig> <pubKey> Here, public key is the Public Key of the sender, A. (this is the public key ...
23
votes
3answers
34k views

Is it possible to get the public key of a bitcoin address I do not have the private keys for with the standard client?

It is possible to get it from here: https://blockchain.info/de/q/pubkeyaddr https://blockchain.info/q Is it possible with the standard client? How? I am aware that the blockchain only contains the ...
20
votes
1answer
15k views

What is a private key and a public key?

What exactly is a private key and public key in relation to Bitcoin? What are they, how are they used, and how does one find out what their private and public keys are?
10
votes
3answers
7k 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: ...
11
votes
1answer
2k views

What are the potential attacks against ECDSA that would be possible if we used raw public keys as addresses?

According to this answer about why addresses are hashes rather than public keys there are potential attacks that are possible if you have the public key rather than the address, what are these attacks?...
14
votes
3answers
20k 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 ...
24
votes
1answer
4k views

Why does hashing public keys not actually provide any quantum resistance?

In the discussions about taproot, it was mentioned that outputs will include the public key directly instead of hashing them. It is stated that, currently, hashing does not really provide quantum ...
6
votes
2answers
3k views

Why is it impossible to derive public key from address?

This is my first bitcoin transaction. Why this transaction doesn't show my public key? help message on the same page says that, It's impossible to determine the public key from a Bitcoin address, ...
7
votes
1answer
8k views

How to generate specific private keys from 12-word backup and wallet address?

A single seed can lead to billions of addresses. Some wallets are unable to scan and find all used addresses. Is it a way to infer the private key from 12-word backup and wallet ID / (public key). ...
1
vote
2answers
4k 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 ...
17
votes
2answers
15k views

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?
14
votes
3answers
7k views

Key derivation in HD wallets using the extended private key vs hardened derivation

I am reading the book Mastering Bitcoin and confused about wallet key derivations in Chapter 4. Keys, Addresses, Wallets. The book first mentions a private child key derivation where the child ...
11
votes
2answers
3k 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?
2
votes
2answers
2k views

What can I do with Account Extended Private Key and Account Extended Public Key?

I have been reading about Account Extended Private Key and Account Extended Public Key that derives from the Master Private Key and Master Public Key, but I still have some question about their ...
8
votes
2answers
5k 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> getPubKey(...
5
votes
1answer
113 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 ...
4
votes
1answer
721 views

Can we derive parent’s private key using child’s private key?

In the book named Mastering Bitcoin by Andreas, the author described the usage of derived child keys. One thing I noted was that he said(page 108), The derivation function is a one-way function, ...
4
votes
3answers
5k 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 ...
2
votes
2answers
998 views

How to list all addresses in a deterministic wallet?

Deterministic wallets generate a key space following established standards, using a random passphrase as seed. I have a couple of questions: How many keys can be generated by a deterministic wallet? ...
2
votes
3answers
1k 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?
2
votes
1answer
102 views

What happens to the overall value of Bitcoin when a huge amount of coin is lost?

My question is 2 part: 1. How does somebody know that a set of bitcoins is lost? Merely declaring that I've lost my private key and hence bitcoin makes the coins lost? 2. What impact(and why?) would ...
2
votes
2answers
2k views

Is that safe to expose public key to the mainnet

Because every time when someone want to spend some money under an address, he need to provide public key and sent the content to the mainnet. (Please correct me if that is not correct) Where can I ...
0
votes
3answers
343 views

What is the math behind Bitcoin's elliptic curve?

I have seen many videos regarding the math behind the bitcoin elliptical curve but none of them show the public key generation. They are just defining few steps. I need the complete math behind the ...
22
votes
2answers
54k 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 ...
9
votes
2answers
38k views

How do I get my public address in Bitcoin Core?

In a world of pain at the moment. I downloaded Bitcoin Core, and before I realised I'd need the complete downloaded Blockchain, my friend transferred some coins to my address. I did some research ...
3
votes
1answer
197 views

How are transactions verified to ensure only the eligible person can spend a Bitcoin balance?

I know each user has a public key and private key. The users signs the transaction with his private key and sends it to a Bitcoin address. What prevents me from claiming his coins? I read something ...
9
votes
2answers
11k 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 ...
4
votes
1answer
11k views

What's the relationship of Bitcoin addresses to public keys?

A Bitcoin wallet can handle multiple private keys. In ECC, you can have 2^256 private keys, and for each key, you can have 2^256 public keys. Assuming that's right (please correct me if I'm wrong), ...
4
votes
2answers
5k views

What is the difference between your address and your public keys

I'm beginning to learn about cryptocurrencies, and I'm having a lot of trouble because some terms are used in different contexts. I know that public keys are generated through a private key. So, are ...
3
votes
1answer
3k views

About performing SHA-256 hashing on the public key

I am following this link, trying to perform SHA-256 on a given public key. However, I cannot get the expected result. I am using the sha256 library in python hashlib The input is ...
3
votes
1answer
5k views

How do I Base58 Checked encode / decode an address in C#? What does "normalize leading zeros" mean?

I am trying to encode and decode a Base58 address in C#. The following function is a start, but it has a few issues: This code does not normalize leading zeros (what does that look like?) If this ...
2
votes
2answers
9k 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 ...
11
votes
5answers
4k views

What would happen if you send bitcoins to a non-existent Bitcoin address?

If one were to send bitcoins to an address that has not been created yet, what would happen? Would the coins be lost forever? Would they just sit there until the address and key pair are generated?
8
votes
3answers
16k views

Is it possible to use xpub address to monitor balance from previously generated addresses?

I'm trying to find a way where I can view balance of my ledger nano s wallet without always attaching it to computer all the time. I found something called xpub address which allows me to generate ...
7
votes
1answer
1k views

If addresses are hashes of public keys, how are signatures verified?

I've skimmed through the https://en.bitcoin.it/wiki/Protocol_specification and it seems that when sending someone bitcoins, I would sign the transaction data (not quite sure which parts exactly) with ...
5
votes
2answers
6k views

How to generate Ed25519 public key from private key using libsodium?

Not all crypto currencies are using secp256k1 technology for keypair generation and digital signatures. Curve25519 technology (frequently used to support ECDH key exchanges) is being used by a few ...
4
votes
1answer
198 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 ...
2
votes
1answer
611 views

How can a sender know receiver's public key when creating "Pay To Public Key" tx?

When you create a "Pay To Public Key" transaction, you need to know the receiver's public key. How can we know receiver's public key? You can get public key hash from address like this, but I'm not ...
1
vote
0answers
1k views

Can Ethereum support compressed secp256k1 public keys to compute Keccak addresses? [closed]

Starting from a private key, a working functional example provides details for how an Ethereum address can be calculated from an uncompressed secp256k1 elliptic curve public key. This functional ...
1
vote
1answer
53 views

Is the `addmultisignature` API call dependent on order of public keys in the array? Or is it lexicographically sorted?

Say Alice and Bob are part of a partnership business that accepts Bitcoin. They store all their main funds in cold storage until the end of 3 months, when they cash out and use a new address. This ...
1
vote
1answer
4k 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: http://procbits.com/2013/08/27/generating-a-bitcoin-address-with-...
9
votes
2answers
9k views

Public Key + Private Key enough to backup?

I invested in bitcoins and unfortunately I have problems to understand the system. Perhaps you can answer me the following questions? 1.a) I know my public and my private key. Do I still have to ...
7
votes
1answer
783 views

How to get the Public Keys of a bitcoin User

Is there some way in which I could get the public key of a Bitcoin user ? Lets say I have transaction with another Bitcoin user. Is there some means by which I can retrieve the public key of the ...
5
votes
2answers
574 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 ...
5
votes
1answer
541 views

Derive new public keys from a public key?

This article says you can generate new public keys from an already generated public key. How is this possible? https://bitcoinmagazine.com/articles/deterministic-wallets-advantages-flaw-1385450276 ...
3
votes
2answers
7k views

Get Master Private Key from BIP39 Seed

I have BIP39 Seed: 5b56c417303faa3fcba7e57400e120a0ca83ec5a4fc9ffba757fbe63fbd77a89a1a3be4c67196f57c39a88b76373733891bfaba16ed27a813ceed498804c0570 I want to get Master private Key Then I Have to ...