# Bitcoin For Dummies

By using our site, you acknowledge that you have read and understand our Cookie Policy , Privacy Policy , and our Terms of Service.

How are the keys are related to the wallet? How can I decide how many Bitcoins to transfer when using my private key? I suppose you know the concept of public key cryptography? If you don't, here is a very short explanation or read the wikipedia page : Public key cryptography as used in Bitcoin , allows you to hand people a public key and use the corresponding private key to prove the ownership.

So you can create any random private key keep it secret and calculate the corresponding public key give it out to public for verification. Using this private key, you can sign a message and other people can verify that you own the private key by using your public key.

A Bitcoin address is just a shorthand notation for a public key. When someone makes a transaction to an address, he states that "I give the right to spend this money to the person who owns the private key corresponding to this address". The person who has received this transaction will in turn be able to spend the transaction by signing the transaction using his private key.

With this signature he can prove that he owns the key, without disclosing it. Others can verify the signature using the public key. As for the second part of your question, it gets a little more advanced. An easy way of viewing it is that every transaction takes a number of inputs and generates a number of outputs.

Inputs in this case are outputs from previous transactions. For each input, the user will have to provide verification he is allowed to spend that output by adding a signature. The "link" to Bitcoin initially happens during block generation where a certain amount of Bitcoin is generated and sent to the miner's public address; this is merely a record in the blockchain.

Then these coins can be sent to other public addresses using transactions. The most simple transaction has one input and one output; i.

To be valid, the amount of output coins must not exceed the amount of input coins, and to be verified the output address hash is signed by the input address' private key. If the amount exceeds what you want to spend, the remainder can be send back to one of the input address or even a new address of your wallet, so you basically send yourself the exceeding amount of Bitcoins.

Any unspent amount in the transaction is considered fee and is collected by the miner generating the block. Transactions can also be much more complex; Bitcoin allows for a very powerful scripting system that can make transactions spendable in many ways. You can read more about bitcoin transactions and scripting system here:.

When you send out a transaction, it is relayed to the network for inclusion in a block if it passes common rules for transactions validity, fee, size, etc. A miner will eventually pick your transaction and include it a block the transactions are actually included in a merkle tree whose root hash is in in the block header - the block header hash is the proof of work that has to match the difficulty requirement for the block.

Podcast: We chat with Major League Hacking about all-nighters, cup stacking, and therapy dogs. Listen now.

Home Questions Tags Users Unanswered. How are public and private keys related to the wallet? Ask Question. Asked 5 years, 11 months ago. Active 2 years, 4 months ago. Viewed 53k times. 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?

Sean Black Sean Black 1 1 gold badge 2 2 silver badges 7 7 bronze badges. Thomas' answer is correct, but I think an easy version may be appreciated as well. So, applied to Bitcoin. Steven Roose Steven Roose WebSockets for fun and profit.

Linked 1. Related 4. Hot Network Questions. Question feed. Bitcoin Stack Exchange works best with JavaScript enabled.

## An example of a bitcoin address in action

By using our site, you acknowledge that you have read and understand our Cookie Policy , Privacy Policy , and our Terms of Service. 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? A private key is just a random number, while the public key is a 2D point coordinate on an Elliptic Curve derived from it. The private key is used to sign messages in case of Bitcoin - the transactions , and the public key is used to check whether the signature is correct. The public key can either be used raw in a transaction, or turned into a Bitcoin address by means of hashing and other operations. There are some online solutions for these tasks, for example my small testing suite website. However, most commonly one leaves key pair generation to the Bitcoin program. If needed be, the private key can be retrieved from the program by using dumpprivkey Bitcoin API call. Podcast: We chat with Major League Hacking about all-nighters, cup stacking, and therapy dogs.

But you keyy still buy, sell and store it in your digital wallet. What makes it possible? And, what are public keys and private keys? Bitcoin utilizes peer-to-peer technology. Money can be transferred from one individual to another directly, without the involvement of any bank. All transactions are recorded on a public ledger. Anyone who has a Bitcoin wallet can send and receive What is bitcoin public key electronically through a PC, smartphone or web app.

Bitcoin is well-known as an electronic cash system, but underneath it all runs a secure messaging system built on the Internet. Instead of relaying emails, texts, or web pages, the Bitcoin network processes value-transfer messages called transactions.

Private keys help authenticate these messages and identify each. Your private key is what is bitcoin public key randomly generated string alphanumericallowing BTC to be spent. A private key is always mathematically related to the crypto wallet keg, but is impossible to reverse engineer thanks to a strong encryption code base. A private key is a secret number generated to allow what is bitcoin public key to spend their coins.

When users are issued a Wgat addressthey are also issued a Bitcoin private key. It is usually a bit number and since it is the golden ticket that allows an individual to spend his or her coins, it needs to be kept safe and secure. The private key is what is bitcoin public key secret sign that is used to decrypt the exchange message. In the traditional method, a secret key is shared within eky to enable encryption and decryption of a message.

But if the key is lost, the system becomes invalid. To avoid this weakness, PKI public key infrastructure came into force where a public key is used along with the private key. PKI enables internet users to exchange information in a secure way with the use of a public and private key. In order to create a transaction, you need to import your private key. However, some wallets may make a transaction without the need of importing the private key. Others will require the private key to bictoin swept.

When private keys pass through the procedure of sweeping, a transaction will be broadcast to another address, which will include the balance. How does one import a Bitcoin private key? One of the methods includes the use of blockchain. This online tool assists users to import private tokens easily. This is achieved through their wallet service which is referred to as a hybrid ewallet.

This is kept on your browser as an encrypted file. You are required to issue your password or alias ;ublic as to access your account. Other private key import providers include Mycelium which provides an Android app.

The app allows one to either scan the code from the paper wallet or by use of cold storage. Any valid transaction bearing a valid signature will be puhlic by the Bitcoin network. At the same time, any person in possession of a private key can sign a transaction. These two facts taken together mean that someone knowing only your private token can steal from you.

Many avenues are open to thieves who steal private tokens. Two of the most popular are storage media and communications channels. For this reason, extreme caution wnat be taken whenever storing or transmitting private keys.

Wallets often place this botcoin in a standard, well-known directory, making it an ideal target for Bitcoin-specific malware. To counter this threat, software wallets offer an option to encrypt the wallet file. Any attacker gaining access to your wallet file would then need to decrypt it.

The difficulty of ls depends on the quality of the encryption and strength of the password being used. Wallet files can be encrypted on many software wallets by bitcion a password. As mentioned earlier, there is also a public key. This causes some confusion, as some people iz that a Bitcoin wallet address and the public key are the. That is not the case, but they are mathematically related.

A Bitcoin wallet whay is a hashed version bitcoih your public key. A public key is obtained by subjecting a private token to a set of mathematical operations defined in a set of standards known as Elliptic Curve Cryptography ECC. Ia a private sign is an integer, a biitcoin key is a 2D coordinate composed of two integers.

To make a public key easier to process, it can be transformed into a single value. One approach appends the y-coordinate to the x-coordinate. A Public key uses asymmetric algorithms that convert messages into an unreadable format.

A person who has a public key can encrypt the message intended for a specific receiver. Keh the receiver with the private token can decode the message, which is encrypted by the public key. The key is available via the public accessible directory.

A private sign, which is just a just click for source such as 42, can be transformed mathematically into a public key. A public token is then transformed into an address. Each of these steps is irreversible. An address results from applying a multi-step transformation to a public key.

Notice that no network is needed at any point in the generation of a private sign or the corresponding address. Every computer on the Bitcoin network knows about the mathematical relationship between public and private signs. This enables each participant to select private keys and sign transactions independently of the Bitcoin what is bitcoin public key. Bitcoin solves problems through a system called public key cryptography.

This system uses two pieces bktcoin information to authenticate messages. A public key identifies a sender or recipient, and can be distributed to.

A private key creates an unforgeable message signature. Public and private keys are mathematically linked through a signature algorithma mathematical procedure for creating identities, signing messages, and validating signatures. Public-key encryption, as opposed to secret-sign encryption, consists of a pair of keys — the public, which is used to encrypt a message and the private, which is subsequently used to decrypt the cipher message.

Each private sign what is bitcoin public key only one matching public key. A message encrypted with the public key can only be decrypted with the related keyy sign. The public key is available to everyone, while the private sign is only known to the wallet holder. There bitcin never a requirement to share a secret sign via an insecure channel. There are 2 broad classes of algorithms — symmetric and asymmetric. Symmetric algorithms use the bitfoin sign for both puhlic and decryption.

Asymmetric encryption is a technique that allows anyone to keh encrypted messages to a receiver. The public key is then published using techniques such as digital certificates. The private key is configured in encryption-enabled software and kept secret. Symmetric encryption is based solely on private signs. For example, symmetric encryption may be used to encrypt data in storage. It is also used in communications by sharing private tokens between endpoints.

In many cases, asymmetric encryption is used to initialize a session and exchange private tokens. Then communication is encrypted with symmetric encryption. This is done because symmetric ehat is faster than asymmetric encryption. The concept of encrypting a message with one key and not being able to decrypt it with the same sign is based on one-way functions. As the name suggests, the characteristic of a one-way kry is that it is wwhat reversible other than with what is bitcoin public key kej and error approach.

This can be achieved if there is an infinite amount of values which lead to the same result, if there is some information lost as part of the algorithm, or if the time to decrypt is immensely longer than to encrypt.

RSA derives its security from the computational difficulty of factoring large integers that are the product of two large prime numbers a prime number or a prime is a natural number greater than 1 that has no positive divisors other than 1 and. Multiplying two large primes is easy, but the difficulty of determining the original botcoin from the total — factoring — forms the basis of public token cryptography security.

The time it takes to factor the product of two sufficiently large primes is considered to be beyond the capabilities of most attackers, excluding nation state actors who may have access to sufficient computing power.

RSA keys are typically or bits long, but experts believe that bit tokens could be broken in the near future, shat is why government and industry are moving to a ket sign length of bits. Note that n is puhlic product of two prime numbers.

It can only be decomposed into p and q. If p and q are large enough then it is de-facto impossible. Digital signatures are based on asymmetric cryptography and can provide assurances of evidence of origin, identity and status of an electronic document, transaction or message, as well as acknowledging informed consent by the signer.

To create a digital signature, signing software such as an email program creates a one-way hash of the electronic data to be signed. The encrypted hash, along with other information such as the hashing algorithm, forms the digital signature. Any change in the data, even to a single bit, results in a different hash value. A digital signature also makes it difficult for the signing party to deny having signed something the property of non-repudiation. If a signing party denies a valid digital signature, their private token has either been compromised, or they are being untruthful.