【目次】 bitcoinjとは？ 特徴 bitcoinj入門 ライセンス ドキュメンテーション 基礎 CoreAPI bitcoinjの動画 高度な機能 コミュニティ bitcoinjとは？ bitcoinjはBitcoinプロトコルを扱うライブラリです。 BitcoinCoreのローカルコピーなしにウォレットを維…

Overview The transaction can hold multiple transaction hashes while keeping the validity of the signature. So, double payment becomes possible by changing the expression without changing the meaning of the input script. This characteristic…

Overview The Mining has two meanings.・Currency supply mecanism ・Decentralized emergent consensus ①Currency supply mechanism At a point of jan 2009, Remuneration of mining for 1 block was 50BTC. In other word, mining means that supply new…

Overiew Blockchain is transaction database shared by all nodes participating in system based on Bitcoin protocol. The full copy of blockchain contains every transaction ever executed in the currency.With this information, one can find out …

Overview Bitcoin is builded as peer-to-peer(P2P) network on internet. P2P network is essentially decentralize and open. This network is formed by connecting mutually equal nodes. we calling computer terminal participating in the network as…

Overiew Transaction is encoded data stracture that value transfer between participants in Bitcoin sistem. Individual transaction add into blockchain as global ledger. Anyone can see each transaction in the blockchain. Basic component of tr…

Overview BIP0038 propose standerd specification that encrypting private key by passphrase and encode in Base58Chack.Even in situation where the key is exposed,It will be able to save to safe backup media and transfer between wallets.When p…

Oveview The type is leading-edge deterministic wallets that are described in BIP 0032.Just have to copy root-seed,You can restore overall HD wallet,backup of millions keys or HD wallet , and export. It can generate public key without users…

Overview Mnemonic code is English words representing random numbers used as Wallet master keys. Passphrase is easy to remember for human beings(passphrase 12 to 24 words). Mnemonic is used to regenerate the seed (master key), regenerating …

Overview Bitcoin has notation method of some kinds in private key and public key.Why Bitcoin has some kinds of notation? Because if you adopted compressed notation, It's possible to reduce the size of the public key by 50%! That means we c…

Overview Bitcoin address represent receiver of funds,it look like bank account. The address produced from public key. Show below example of a bitcoin address:Bitcoin address example 15oYSxBcM5deLicKoqwNL2iuAJXpdoc3GL ※27-32 digit alphanume…

Overview Public key indicate to destination of funds. The public key is private key encrypted with elliptic curve cryptography.Public key example 0458e0d3f7cd6d54347a25523dee480199e59541d849abcd4223538397ded94 e30f4f10af03bb48a1af2051c529f…

Overview This article speaks about elliptic curve to base on Elliptic Curve Cryptography(ECC).y^2=x^3+ax+bWhen this equation solution equal "zero",the point connection become elliptic curve. case of a=-1,b=1: y^2 = x^3 - x + 1 Finite field…

Overview One of the key pairs in public key cryptography is the private key. Use the private key to control access to transaction. Private key was chosen randomly integer (256 bit) from between 1 to p. "p" is「2^256 - 2^32 - 2^9 - 2^8 - 2^…

Overview Bitcoin adopts public key cryptography for bitcoin exchange. By knowing about algorism of public key cryptography, easy to get understanding about private key and public key. Now I'd like to talk about cryptography used some publi…