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Blockchain Technology

massive dense linear structures. It guarantees that the outcome is correct by compar­

ing it against different servers. Eyal et al. (2016) proposed “Next-generation Bitcoin”

for blockchain (Eyal et al., 2016). The purpose was to incorporate a component that

does not influence another block key portion. A “strong block” is a node with a sig­

nificant number of votes from the rest of the network. The block size is redesigned to

retain both block size and transaction costs.

11.5.2  Data Theft

The blockchain is a very secure method to share digital tokens, since it only enables

people to make transfers using a reference key. Users may create multiple addresses,

making it difficult to trace when information leaks. However, Kosba et al. (2016)

demonstrated that blockchains with a wallet, including a public key and transaction

records, cannot guarantee transaction anonymity in an entirely general P2P model

(Kosba et al., 2016). Besides, the study conducted by Barcelo (2014) suggested that

it is possible to connect a user’s Bitcoin transaction to disclose their details. Many

approaches are proposed to enhance blockchains’ privacy, divided into semi-anon­

ymous and anonymous forms. On the blockchain, addresses record pseudonymous

interactions. And with all of these safeguards, it is always possible to connect a

speech to the consumer’s actual identity via transaction history, so the user must be

cautious. In semi-anonymous mixing, the transfer is made from many individuals to

a single or many individuals without disclosing the person’s identification (Ruffing

et al., 2014). Miners are allowed to verify a transaction via digital signature. Instead

of validating the coins themselves, the miner only makes sure that the blockchain’s

currency belongs to a valid coin registry. To avoid information leakage to the work­

stations, the payment’s fund balance is not associated with the blockchain transac­

tion. It still shows the sources and the sums of the expenses. One proposed method,

named Zero cash, aims to overcome the Zero coin’s privacy issue. In combination

with zero-knowledge proofs, zero cash’s lightning-speed transaction mechanism is

brought to fruition. According to purchase quantities and user values, one does not

realize how much a user is paying.

11.5.3  Greedy Exploitation

Blockchain is open to exploitation by greedy miners. As a general rule, it is thought

that 51 percent of nodes could break the blockchain and that the transaction did in

fact take place. However, the system is fragile even if it is not 51% controlled. The

list can become unreliable if only a small amount of hash power is used. The min­

ers excavate unrevealed blocks without exchanging the freshly found branches with

any other groups. The private track is longer than the current public path, going into

operation with fair approval from both miners. Miners’ capital would be invested

without private blockchains, although dishonest miners extract money without

opponents. Selfish individuals gain more income than others. If a greedy miner has

ownership of the pool, there is a fair risk that 51% mining will occur. There have

been mining attacks that showed blockchain is not as reliable as has been supposed.