Jump to: navigation, search Elliptic Curve Digital Signature Algorithm or ECDSA is a cryptographic algorithm used by Bitcoin to ensure that funds can only be spent by their rightful owners.A few concepts related to ECDSA: private key: A secret number, known only to the person that generated it.A private key is essentially a randomly generated number.In Bitcoin, someone with the private key that corresponds to funds on the public ledger can spend the funds.In Bitcoin, a private key is a single unsigned 256 bit integer (32 bytes).public key: A number that corresponds to a private key, but does not need to be kept secret.A public key can be calculated from a private key, but not vice versa.A public key can be used to determine if a signature is genuine (in other words, produced with the proper key) without requiring the private key to be divulged.In Bitcoin, public key are either compressed or uncompressed.Compressed public keys are 33 bytes, consisting of a prefix either 0x02 or 0x03, and a 256-bit integer called x.

The older uncompressed keys are 65 bytes, consisting of constant prefix (0x04), followed by two 256-bit integers called x and y (2 * 32 bytes).The prefix of a compressed key allows for the y value to be derived from the x value.signature: A number that proves that a signing operation took place.A signature is mathematically generated from a hash of something to be signed, plus a private key.The signature itself is two numbers known as r and s. With the public key, a mathematical algorithm can be used on the signature to determine that it was originally produced from the hash and the private key, without needing to know the private key.Signatures are either 73, 72, or 71 bytes long, with probabilities approximately 25%, 50% and 25% respectively, although sizes even smaller than that are possible with exponentially decreasing probability.Elliptic Curve Digital Signature Algorithm - Wikipedia articleThis article describes a process for creating bitcoin addresses from a book cipher.The private key of the Bitcoin address can be re-generated in the future as long as you remember the book or text you used.

A book cipher Book Cipher - Wikipedia is a cipher in which the key is some aspect of a book or other piece of text.There are several ways to use a book to create a coded message.For instance the Beale code uses the word number to encode the location of hidden treasure.Bitcoin is based on public key cryptography.Generally you would have a digital wallet containing a number of cryptographic keypairs.A key pair contains a public key and a private key.People can make payments to your public key address and you can spend them by using your private key address.Every Bitcoin private key is a 32-byte hex number and any 32-byte hex number can be used as a Bitcoin private key.The public key of a Bitcoin address is a hash of the private key using the RIPMD-160 hash algorithm.An example Bitcoin key pair generated by vanitygen is shown below.(Vanitygen uses Base58 to display the private key.)The SHA256 hash algorithm coincidentally will produce a 32-byte hex number from any text input.

An example using unix runs as follows.or, we can run this through gpg.So we have a way of generating Bitcoin private keys with a passphrase.Let's go one step further and use a book cipher to create a passphrase and then the corresponding key is the reminder for that passphrase key so that 5 years down the line as long as we can remember what book we used we can use the book cipher key to generate our passphrase.bitcoin pacmanI'm going to use a page number/line number/word number syntax to describe my passphrase.bitcoin pleaSo I pick a book from my book shelf and I flick through and pick a few random words.bitcoin nasıl satılırTurn the passphrase into a bitcoin private key.bitcoin core raspberry pi 2

I can then use a base conversion tool Such as this one to convert the Base16 (Hexadecimal) address to Base58, which gives me.Currently the bitcoin client doesn't support private key import although there is a pull request to implement this functionality.litecoin source codeThere are also a bunch of tools that can work directly on a wallet.dat file for key import.litecoin mining chinaBitcoin tools has functionality to create Bitcoin addresses from a sentence and also has a facility to download a wallet.dat so the coins can be spent.avalon ii bitcoinUse the "Generate key from a sentence" feature in Brand to create a key pair.why bitcoin difficulty increaseBrand has a clue field which is a place to store a reminder of your strong password.bitcoin conference ireland

In this case you could enter your page and word keys for storage.If you select the "Generate Paper Wallet" option on the accounts page of Brand you'll get a PDF document of your accounts.This is useful backup of your accounts as you can retrieve your Bitcoin keys independently of Brand .Jump to: , A private key in the context of Bitcoin is a secret number that allows bitcoins to be spent.Every Bitcoin wallet contains one or more private keys, which are saved in the wallet file.The private keys are mathematically related to all Bitcoin addresses generated for the wallet.Because the private key is the "ticket" that allows someone to spend bitcoins, it is important that these are kept secure.Private keys can be kept on computer files, but in some cases are also short enough that they can be printed on paper.Some wallets allow private keys to be imported without generating any transactions while other wallets or services require that the private key be swept.When a private key is swept, a transaction is broadcast that sends the balance controlled by the private key to a new address in the wallet.

Just as with any other transaction, there is risk of swept transactions to be double-spending.In contrast, bitcoind provides a facility to import a private key without creating a sweep transaction.This is considered very dangerous, and not intended to be used even by power users or experts except in very specific cases.Bitcoins can be easily stolen at any time, from a wallet which has imported an untrusted or otherwise insecure private key - this can include private keys generated offline and never seen by someone else[1][2].Contents 1 2 3 4 5 6 7 In Bitcoin, a private key is usually a 256-bit number (some newer wallets may use between 128 and 512 bits), which can be represented one of several ways.Here is a private key in hexadecimal - 256 bits in hexadecimal is 32 bytes, or 64 characters in the range 0-9 or A-F. Nearly every 256-bit number is a valid ECDSA private key.Specifically, any 256-bit number from 0x1 to 0xFFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4140 is a valid private key.

The range of valid private keys is governed by the secp256k1 ECDSA standard used by Bitcoin.Newer wallets may use BIP 32 seeds for their private keys, which can be as long as 512 bits.When importing or sweeping ECDSA private keys, a shorter format known as wallet import format is often used, which offers a few advantages.The wallet import format is shorter, and includes built-in error checking codes so that typos can be automatically detected and/or corrected (which is impossible in hex format) and type bits indicating how it is intended to be used.Wallet import format is the most common way to represent private keys in Bitcoin.For private keys associated with uncompressed public keys, they are 51 characters and always start with the number 5 on mainnet (9 on testnet).Private keys associated with compressed public keys are 52 characters and start with a capital L or K on mainnet (c on testnet).This is the same private key in (mainnet) wallet import format: When a WIF private key is imported, it always corresponds to exactly one Bitcoin address.

Any utility which performs the conversion can display the matching Bitcoin address.The mathematical conversion is somewhat complex and best left to a computer, but it's notable that the WIF guarantees it will always correspond to the same address no matter which program is used to convert it.The Bitcoin address implemented using the sample above is: 1CC3X2gu58d6wXUWMffpuzN9JAfTUWu4Kj Some applications use the mini private key format.Not every private key or Bitcoin address has a corresponding mini private key - they have to be generated a certain way in order to ensure a mini private key exists for an address.The mini private key is used for applications where space is critical, such as in QR codes and in physical bitcoins.The above example has a mini key, which is: Any Bitcoins sent to the address 1CC3X2gu58d6wXUWMffpuzN9JAfTUWu4Kj can be spent by anybody who knows the private key implementing it in any of the three formats, regardless of when the bitcoins were sent, unless the wallet receiving them has since made use of the coins generated.