Unspent Transaction Output Research Articles

A blockchain based decentralized data security mechanism for the Internet of Things

The Internet of Things (IoT) is the core infrastructure of the smart city information system. With the explosive growth of IoT devices, how to securely maintain the important data generated by IoT devices has become an important issue. In the conventional IoT-cloud based infrastructure, the sensitive IoT data was stored in a third cloud service provider. However, in such a manner, the private IoT data may be disclosed by the cloud server since the cloud server knows all the data stored in it. This paper, for the first time, proposes a decentralized secure mechanism based on the blockchain technique to store the important data generated in the IoT system. This mechanism effectively solves the data reliability, security and privacy issues that may be encountered in the conventional IoT-cloud system. Considering the defects of simplified payment verification used by light nodes in blockchain networks, this paper proposes an Unspent Transaction Output (UTXO) verification mechanism based on the RSA accumulator, which makes the computational complexity of light nodes to generate and verify the UTXO proof to be constant. The proposed mechanism not only provides proof of inclusion but also supports efficient proof of exclusion for a lightweight node. Our experiment results indicate that the proposed scheme is practical and efficient.

Preventing the bitcoin Double Spend using Transaction Hash and Unspent Transaction Output

The red-hot crypto currency is a bitcoin which occupies first position in the capital investment of financial world which is assaulted by various factors like wallet attacks, network attacks, mining attacks and double spending attacks. Double spending is the major attack in which the attacker tries to cheat the network nodes and use the same coin for more than one set of transactions. Of this the original transaction identification from the set of transactions is a challenging one. In this paper we propose a solution for identifying the primary transaction from the set of double spended or multi spended transactions. The proposed approach finds the authentic transaction from the list of double spended transactions using transaction hash value, which is primarily used for every transaction in the Bitcoin network. Transaction hash value is used as transaction identifier for each bitcoin transaction. By comparing the transaction hash value with the existing pool of unconfirmed input pool, transhash pool and utxopool one can identify the genuine transaction from the flawed transaction list. The firsthand transaction is then added to the Confirmed input pool which is then entered into the newly added block of the blockchain. This architecture will prevent the double spend of bitcoin further in the network which facilitates the network nodes as well as minimize the miners task for verification and validation of transaction.

Another coin bites the dust: an analysis of dust in UTXO-based cryptocurrencies.

Unspent Transaction Outputs (UTXOs) are the internal mechanism used in many cryptocurrencies to represent coins. Such representation has some clear benefits, but also entails some complexities that, if not properly handled, may leave the system in an inefficient state. Specifically, inefficiencies arise when wallets (the software responsible for transferring coins between parties) do not manage UTXOs properly when performing payments. In this paper, we study three cryptocurrencies: Bitcoin, Bitcoin Cash and Litecoin, by analysing the state of their UTXO sets, that is, the status of their sets of spendable coins. These three cryptocurrencies are the top-3 UTXO-based cryptocurrencies by market capitalization. Our analysis shows that the usage of each cryptocurrency presents some differences, and led to different results. Furthermore, it also points out that the management of the transactions has not always been performed efficiently and therefore, the current state of the UTXO sets is far from ideal.