<p>No, there is no enforcement that a private key exists. </p>

<p>However, due to a Bitcoin address including a checksum, it is very unlikely for the client to create a transaction when for an address with a typo, paste error, or other erroneous data.  There are addresses that will pass the checksum test in which, presumably, no private key exists. <a href="http://blockexplorer.com/address/1BitcoinEaterAddressDontSendf59kuE" rel="nofollow">1BitcoinEaterAddressDontSendf59kuE</a> is, in all likelihood, one such address.</p>

CC BY-SA 3.0
2013-04-19T01:44:35.320Z
That's what I thought. Thanks for the fast answer
Charles Hoskinson
CC BY-SA 3.0
2013-04-19T12:02:46.787Z
Also, that would mean you would need tons of additional information to form a transaction, including the public key which you currently don't need. It would kind of defeat the whole point of addresses.
David Schwartz
CC BY-SA 3.0
2013-04-19T01:19:08.417Z
2013-04-19T01:19:08.417Z
Stephen Gornick
<p>Apologies if this question has been asked before, but when a bitcoin client wishes to send funds to an address, does the bitcoin protocol force the client to verify that the address has a corresponding private key? </p>

<p>For example, I am given an address and I want to send a btc to this address, before I am allowed to authorize this transaction does the bitcoin protocol force me to verify that the address can decrypt a message encrypted from its public key?</p>

CC BY-SA 3.0
2013-04-19T01:13:46.817Z
Transactions are not encrypted.  They do use cryptographic signed messages though.
Stephen Gornick
CC BY-SA 3.0
2013-04-19T01:46:06.450Z
I'm aware that transactions are not encrypted but the address we send money to is part of a public private key pair. One could verify that the address is legitimate by requiring the receiver to encrypt and decrypt a test message with his pub-pri keypair
Charles Hoskinson
CC BY-SA 3.0
2013-04-19T01:49:29.653Z
The checksum scheme seems to fail for one in four billion addresses. Yes this is sufficient
Charles Hoskinson
<cryptography>
Address Public Private key verification
Charles Hoskinson
# Address Public Private key verification

(Asked by: username_0 on 2013-04-19)

Apologies if this question has been asked before, but when a bitcoin client wishes to send funds to an address, does the bitcoin protocol force the client to verify that the address has a corresponding private key?

For example, I am given an address and I want to send a btc to this address, before I am allowed to authorize this transaction does the bitcoin protocol force me to verify that the address can decrypt a message encrypted from its public key?

**Tags:** cryptography

> **Comments:**
> **username_1**: Transactions are not encrypted.  They do use cryptographic signed messages though.  
> **username_0**: I'm aware that transactions are not encrypted but the address we send money to is part of a public private key pair. One could verify that the address is legitimate by requiring the receiver to encrypt and decrypt a test message with his pub-pri keypair  
> **username_0**: The checksum scheme seems to fail for one in four billion addresses. Yes this is sufficient  

---

## 1 answers

### Answer by username_1 on 2013-04-19. Score: 3 | Accepted answer

No, there is no enforcement that a private key exists.

However, due to a Bitcoin address including a checksum, it is very unlikely for the client to create a transaction when for an address with a typo, paste error, or other erroneous data. There are addresses that will pass the checksum test in which, presumably, no private key exists. [1BitcoinEaterAddressDontSendf59kuE](http://blockexplorer.com/address/1BitcoinEaterAddressDontSendf59kuE) is, in all likelihood, one such address.

> **Comments:**
> **username_0**: That's what I thought. Thanks for the fast answer  
> **username_2**: Also, that would mean you would need tons of additional information to form a transaction, including the public key which you currently don't need. It would kind of defeat the whole point of addresses.  

---

