Block chain question and answer day3

Block chain question and answer day3

Bitcoin transactions are done how?

The most common type of transaction in two ways: receiving address (P2PKH, Pay-to-Public-Key-Hash), and to receive public address hash hash of transaction transaction script (P2SH, Pay-to-Script -Hash), the two transactions are collectively referred to as the standard type of transaction.

What is P2PKH?

Most transactions on the Bitcoin network is P2PKH, the output of such transactions is to give a public key hash, that is, we often say that Bitcoin address.

What is P2SH?

P2SH as a transaction type can greatly simplify the complex transaction scripts introduced in 2012. The output value of such transactions is the script S through Hash160 process. S is ReedeemScript, it is an honor script, the script itself can achieve some of the features, such as multiple signatures. Multi-signature received address is not in the usual sense of the address, but a synthesis address. M need to provide signatures of the n if the cost, then this method is called n-of-m type. We can say that the introduction of P2SH type of transaction, the Bitcoin system can achieve some simple intelligence contracts, enhance its Turing sex.

After the introduction of isolation witness (Segregated Witness), Bitcoin transaction types increased P2WPKH (Pay-to-Witness-Public-Key-Hash) and P2WSH (Pay-to-Witness-Script-Hash) both.

Bitcoin transaction structure is what?

# 交易记录的完整结构
class 交易数据结构:
    版本号 = 4 byte # 明确这笔交易参照的规则
    输入个数 = 1~9 byte # 被包含的输入数量
    
    输入列表 = 不定 # 一个或多个交易输入（块中第一块交易也叫Coinbase交易）
    class 输入字段数据结构:
        上一个交易的散列值（使用交易的散列值） = 32 byte # 对交易进行双重散列（SHA256）指向交易包含的被花费UTXO的散列指针
        输出索引 = 4 byte # 被花费UTXO的索引号，第一个是0
        解锁脚本长度 = 1~9 byte # 用字节表示后面的解锁脚本长度
        输入（解锁）脚本 = 变长 # 一个达到UTXO锁定脚本中条件的脚本
        序列号 = 4 byte # 一般是0xFFFFFFFF，除非lock_time>0
            
    输出个数 = 1~9 byte # 被包含的输出数量
    
    输出列表 = 不定 # 一个或多个交易输入（块中第一块交易的输出是挖矿奖励）
    class 输出字段数据结构:
        输出值 = 8 byte # 以聪为单位表示比特值
        锁定脚本长度 = 1~9 byte # 用字节表示后面的锁定脚本长度
        输出（锁定）脚本 = 变长 # 一个定义了支付输出所需条件的脚本
        
    锁定时间 = 4 byte # 如果锁定时间不为0且小于0xFFFFFFFF，那么可以设定交易的解锁条件，如块高度或时间

Using bitcoin-core of getrawtransaction command to view transaction data, the following is getrawtransaction command returns the data format and meaning of the data.

{
    "hex":"data",   (string) The serialized, hex-encoded data for 'txid'
    "txid":"id",    (string) The transaction id (same as provided)
    "hash":"id",    (string) The transaction hash (differs from txid for witness transactions)
    "size":n,       (numeric) The serialized transaction size
    "vsize":n,      (numeric) The virtual transaction size (differs from size for witness transactions)
    "weight":n,     (numeric) The transaction's weight (between vsize*4-3 and vsize*4)
    "version":n,    (numeric) The version
    "locktime":ttt, (numeric) The lock time
    "vin":[         (array of json objects)
        {
            "txid":"id",    (string) The transaction id
            "vout":n,       (numeric)
            "scriptSig":{   (json object) The script
                "asm":"asm",    (string) asm
                "hex":"hex",    (string) hex
            },
            "sequence":n,   (numeric) The script sequence number
            "txinwitness":["hex", ...] (array of string) hex-encoded witness data (if any)
        }
        ,...
    ],
   "vout":[     (array of json objects)
        {
            "value":x.xxx,      (numeric) The value in " + CURRENCY_UNIT + "
            "n":n,              (numeric) index
            "scriptPubKey":{    (json object)
                "asm":"asm",    (string) the asm
                "hex":"hex",    (string) the hex
                "reqSigs":n,    (numeric) The required sigs
                "type":pubkeyhash, (string) The type, eg 'pubkeyhash'
                "addresses":[   (json array of string)
                    "adress"    (string) bitcoin address
                    ,...
                ]
            }
        }
        ,...
   ],
   "blockhash":"hash",      (string) the block hash
   "confirmations":n,       (numeric) The confirmations
   "time":ttt,              (numeric) The transaction time in seconds since epoch (Jan 1 1970 GMT)
   "blocktime":ttt          (numeric) The block time in seconds since epoch (Jan 1 1970 GMT)

Analysis of the structure of the transaction by this transaction ID 028cfae228f8a4b0caee9c566bd41aed36bcd237cdc0eb18f0331d1e87111743

# ~ bitcoind getrawtransaction 028cfae228f8a4b0caee9c566bd41aed36bcd237cdc0eb18f0331d1e87111743 1
{ 
"hex" : # (字符串)序列化的16进制编码的交易'txid'数据
"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", 

"txid" : # （字符串）交易索引（和传入的一样）
"028cfae228f8a4b0caee9c566bd41aed36bcd237cdc0eb18f0331d1e87111743", 
"version" : 1, # （数字）版本
"locktime" : 0, # （数字）锁定时间
"vin" : [ # （json对象数组）
    { 
        # （字符串）交易索引
        "txid" : "b79a4803014177ea0139c95f09c6903c01bb8f80d039631afd68cabf7eb0f3c9", 
        # （数字）
        "vout" : 0, 
        # （json对象）脚本
        "scriptSig" : { 
            # （字符串）脚本公钥和签名
            "asm" : "3044022055bac1856ecbc377dd5e869b1a84ed1d5228c987b098c095030c12431a4d5249022055523130a9d0af5fc27828aba43b464ecb1991172ba2a509b5fbd6cac97ff3af01 048aefd78bba80e2d1686225b755dacea890c9ca1be10ec98173d7d5f2fefbbf881a6e918f3b051f8aaaa3fcc18bbf65097ce8d30d5a7e5ef8d1005eaafd4b3fbe", 
            # （字符串）16进制公钥
            "hex" : "473044022055bac1856ecbc377dd5e869b1a84ed1d5228c987b098c095030c12431a4d5249022055523130a9d0af5fc27828aba43b464ecb1991172ba2a509b5fbd6cac97ff3af0141048aefd78bba80e2d1686225b755dacea890c9ca1be10ec98173d7d5f2fefbbf881a6e918f3b051f8aaaa3fcc18bbf65097ce8d30d5a7e5ef8d1005eaafd4b3fbe" 
            }, 
        "sequence" : 4294967295 # （数字）脚本序列号，4294967295=0xffffffff
    }, 

    { 
        "txid" : "b79a4803014177ea0139c95f09c6903c01bb8f80d039631afd68cabf7eb0f3c9", 
        "vout" : 1, 
        "scriptSig" : { 
            "asm" : "304402206b993231adec55e6085e75f7dc5ca6c19e42e744cd60abaff957b1c352b3ef9a022022a22fec37dfa2c646c78d9a0753d56cb4393e8d0b22dc580ef1aa6cccef208d01 042ff65bd6b3ef04253225405ccc3ab2dd926ff2ee48aac210819698440f35d785ec3cec92a51330eb0c76cf49e9e474fb9159ab41653a9c1725c031449d31026a", 
            "hex" : "47304402206b993231adec55e6085e75f7dc5ca6c19e42e744cd60abaff957b1c352b3ef9a022022a22fec37dfa2c646c78d9a0753d56cb4393e8d0b22dc580ef1aa6cccef208d0141042ff65bd6b3ef04253225405ccc3ab2dd926ff2ee48aac210819698440f35d785ec3cec92a51330eb0c76cf49e9e474fb9159ab41653a9c1725c031449d31026a" 
            }, 
        "sequence" : 4294967295
    }, 

    { 
        "txid" : "da30b272fb73d78108ff80ddd1ac2f76419533af79ad06a5b3c70fc4a62086c9", 
        "vout" : 1, 
        "scriptSig" : { 
            "asm" : "3045022040a5d957e087ed61e80f1110bcaf4901b5317c257711a6cbc54d6b98b6a8563f02210081e3697031fe82774b8f44dd3660901e61ac5a99bff2d0efc83ad261da5b4f1d01 04a7d1a57e650613d3414ebd59e3192229dc09d3613e547bdd1f83435cc4ca0a11c679d96456cae75b1f5563728ec7da1c1f42606db15bf554dbe8a829f3a8fe2f", 
            "hex" : "483045022040a5d957e087ed61e80f1110bcaf4901b5317c257711a6cbc54d6b98b6a8563f02210081e3697031fe82774b8f44dd3660901e61ac5a99bff2d0efc83ad261da5b4f1d014104a7d1a57e650613d3414ebd59e3192229dc09d3613e547bdd1f83435cc4ca0a11c679d96456cae75b1f5563728ec7da1c1f42606db15bf554dbe8a829f3a8fe2f" 
            }, 
        "sequence" : 4294967295 
    } 
], 

"vout" : [ 
    { 
        "value" : 0.84000000, # （数字）以BTC为单位的金额
        "n" : 0, # （数字）索引/序号
        "scriptPubKey" : 
        { 
            "asm" : "OP_DUP OP_HASH160 634228c26cf40a02a05db93f2f98b768a8e0e61b OP_EQUALVERIFY OP_CHECKSIG", 
            "hex" : "76a914634228c26cf40a02a05db93f2f98b768a8e0e61b88ac", 
            "reqSigs" : 1, 
            "type" : "pubkeyhash", 
            "addresses" : [ 
                "1A3q9pDtR4h8wpvyb8SVpiNPpT8ZNbHY8h" 
                ] 
        } 
    }, 

    { 
        "value" : 156.83000000, 
        "n" : 1, 
        "scriptPubKey" : { （json对象）
            # （字符串）脚本公钥
            "asm" : "OP_DUP OP_HASH160 7514080ab2fcac0764de3a77d10cb790c71c74c2 OP_EQUALVERIFY OP_CHECKSIG", 
            # （字符串）16进制公钥
            "hex" : "76a9147514080ab2fcac0764de3a77d10cb790c71c74c288ac", 
            "reqSigs" : 1, # （数字）需要的签名
            "type" : "pubkeyhash", # （字符串）类型，例‘pubkeyhash’
            "addresses" : [ # （json字符串数组）
                "1Bg44FZsoTeYteRykC1XHz8facWYKhGvQ8" # （字符串）比特币地址 
                ] 
        } 
    } 
], 
# （字符串）区块哈希
"blockhash" : "0000000000007c639f2cbb23e4606a1d022fa4206353b9d92e99f5144bd74611", 
"confirmations" : 147751, # （数字）确认数
"time" : 1301705313, # （数字）从格林尼治时间 1970-01-01 00:00:00 开始以秒为单位的交易时间
"blocktime" : 1301705313 # （数字）从格林尼治时间 1970-01-01 00:00:00 开始以秒为单位的区块创建时间
} 

What is UTXO?

Bitcoin transaction "cost" is a transaction output unused called UTXO (Unspend Transaction Output).

Bitcoin has no notion of accounts, transaction flow using a similar way to record the whereabouts of Bitcoin. If you want to know the address of the current number of Bitcoin can use, we must look into the past of this address all transactions UTXO then added. And any amount UTXO only be used once, in the use of the process will take one or more UTXO, but also produce one or more UTXO.

If Alice's address there are two UTXO, a UTXO Calor is transferred to the 3BTC, Dave is a transfer of 2BTC. Then Alice wants Bob to turn 4.5BTC, then the transaction input Alice structure including txid two transactions, the two pen is transferred to Calor and Dave Alice BTC produced. Two transactions together have input 5BTC, but Alice just give Bob turn 4.5BTC, then Alice transaction structure had two pens output, a sum to Bob 4.5BTC, a sum to their 0.5BTC.

Upon completion of the transfer of two UTXO Alice used to consume, because the miners in the mining verifies whether UTXO before being used. But also generated a new sum transferred to Alice 0.5BTC of UTXO.