Friends who have experienced bitcoin transactions should know that the confirmation of bitcoin transfer transactions is very slow. Frequent congestion of bitcoin networks has been criticized by many people. Congestion of blockchain network will inevitably lead to problems such as slow transfer time and high transfer cost.
Isolating witnesses is put forward to solve this problem.
The English full name of isolated witness is Segregated wit, abbreviated as SegWit, which means to isolate the verification information and then process the verification information separately.
In order to make the blockchain carry more transactions, isolated witness is designed, and the information on the blockchain is divided into transaction information and witness information.
The transaction information is who transferred how much money to whom when. Witness information is the signature information of the transaction, which is used to verify whether the initiator of the transaction has the right to use these digital currency.
When designing Bitcoin, Satoshi Nakamoto directly put these two pieces of information in a block, in which witness information takes up about two thirds of the space, so a block can't carry more transaction information. Ordinary users only need to know the transaction information, and only miners need to verify the witness information.
In this way, the witness information can be taken out of the block, put in another space and handed over to the miners for verification. Only transaction information is recorded in the block, so the block can also carry more transaction information without changing the block size. So as to achieve the purpose of block expansion, improve the transaction efficiency of the network within the bitcoin block, speed up the transaction and reduce the transaction cost.
For hardware wallets, the security impact of isolated witness is enormous.
The hardware wallet is not stored in the blockchain, nor can it directly access the bitcoin network. When the user needs to use the hardware wallet client to construct a bitcoin transaction and send a certain amount to an address, if the input and output information of the transaction can be confirmed to be true, the transaction data can be sent to the hardware wallet for transaction signature. ?
The transaction input amount needs to be carried in the signature data of the isolated witness, and the transaction fee can be calculated by extracting the output amount from the transaction output. ?
Before the isolated witness is realized, the data sent to the hardware for signature does not include the amount of transaction input, and the handling fee cannot be calculated by the data on the hardware itself, which gives hackers an opportunity. If a hacker uses too many transaction inputs to construct a transaction, it may cause a huge handling fee to the user while ensuring that the transaction output is normal, and make the hardware wallet users suffer heavy losses.
Happily, LUBANSO hardware wallet will soon support isolated witness. By then, users of Lubanzo X 1 Hardware Wallet can reduce transaction procedures, speed up transaction confirmation and reduce the risk of commission attack.