What is a public key of a cryptocurrency wallet (Bitcoin address)?

A pair of keys (private and public) are the main tools that allow you to use a cryptocurrency wallet and perform any operations with assets.

We already talked about what a private key is in one of the articles, and in this article we will talk about what a public key is.

What is a public key and what does it look like?

A public key is a unique character set consisting of letters and numbers. This is the address to which other users can send cryptocurrency . The second name is the address of the cryptocurrency wallet.

The public key is tied to private. However, if the latter is secret information, then the public key is public, and everyone can track it in the blockchain (in this article we will talk about the Bitcoin address). The public key has several formats, each of which is easily converted to another.

The public key consists of 26-35 characters, which can be letters of the Latin alphabet (except O, l and I) in lower and upper case and numbers (except 0). Bitcoin address looks like this:

1EhAppLe4FaBiTca1NADr3sSV56sGaMG6hP

Also, when creating a wallet, a user gets a public key in the form of a QR code for ease of use – if you need to send bitcoins to a specific address, you can simply scan the code.

Types of public keys

There are two types of public keys.

Normal – starts from 1, and to receive funds for it, the user must confirm what the private key knows. It looks like this:

1EhAppLe4FaBiTca1NADr3sSV56sGaMG6hP

The second option is a public key with a multi-signature. It starts from 3, and the user must have more than one private key to receive funds. An example of a multi-signature key:

3J65t1WtET25CNrQvie543iWadfRhPaLy

How to find out your public key?

If you are using a bitcoin wallet , then the public key can be found in the settings. If you have only a private key, then the easiest way is to transfer it to the wallet, and then find it in the interface.

The storage location of the address depends on the wallet used, but usually there are two options:

1. Go to Settings – Addresses. In some wallets, the default is to create a new address for each incoming transaction. This is done to increase the anonymity of the user. But if you do not need this function, you can change the settings by ticking the option “Eternal address”. But nothing terrible will happen if cryptocurrencies are sent to any of the addresses already used before – they will simply be redirected to the current one. To see all the addresses associated with the private key, you need to go to the "Address Management" section.
2. Go to "Wallet – Balance" and click on the purse recharge button. The line “Wallet address to replenish your balance” will appear on the screen – this is the actual public key that can be copied and transferred to the sender.

The role of the address in sending transactions

The main role of the public key is to specify the path to which the bitcoins will be sent. However, in order to receive funds, it is necessary to know the private key.

Also, if you are not sure that the address belongs to a specific person, there is a way to verify this. The user can ask the owner of the address to send a signed message. Using the algorithm, miners verify that the private and public key from the received message is one pair, and the message has been signed by the real recipient. Thus, you can make sure that the address is really correct, and you will not send bitcoins into "non-existence".

Bitcoin address usage system

First of all, you need to understand that the address and wallet are not the same thing. An address or private key is a “path” that allows transactions to be received. A wallet is software that essentially consists of a private key and one or many public keys. It stores information about all previously used keys, as well as incoming and outgoing bitcoin transactions. In addition, additional functions can be built into the wallet that increase the anonymity of transactions.

And now how the transaction technically passes.

After the private key is generated, a public key consisting of a number of characters (maximum 35) is created on its basis and displayed on the screen as a QR code.

When a private key is reused, a randomized public key is generated on its basis. But, as mentioned above, this feature can be disabled and use the "eternal" address. Each key weighs about 500 bytes, so that even on mobile wallets you can store many addresses.

The process of generating public keys is based on a random selection of symbols and the solution of complex mathematical problems. In a minute, the algorithm can create up to 1000 addresses, and some software allows you to generate public keys without going online. There is a very small probability that the same public one will be tied to two different private keys, but it is only 1:43 billion.

When you enter an address, you need to be extremely careful and cautious, because an error even in one symbol will result in bitcoins simply not reaching the recipient, and the transactions in the blockchain are irreversible. That is why it is recommended to copy the address or send the cryptocurrency by scanning the QR code of the private key.

Those who are just acquainted with the world of cryptocurrency, it is very important to understand the role and value of public keys, since the correct handling of them ensures that the transaction reaches its recipient. Also, knowing the principle of generating and operating Bitcoin addresses, you can make transactions more anonymous. In any case, before clicking on the “Send” button, it is better to double-check the correctness of the entered address, or to use QR codes for greater confidence.

Publication date 05/06/2019
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