Analyze Cyber Attacks in Cloud Cryptography and Short Comings in Blockchain Cryptocurrency Ravikumar Ch 1 , Dr. Isha Batra 2 and Dr Arun Malik 3 1 Computer Science and Engineering, Lovely Professional University, Punjab, India. 2 Computer Science and Engineering, Lovely Professional University, Punjab, India. 3 Computer Science and Engineering, Lovely Professional University, Punjab, India. E-mail: chrk5814@gmail.com, isha.17451@lpu.co.in,arun.17442@lpu.co.in Abstract: Technological improvements have happened in companies digitalizing various elements of their actions. The threat landscape of cyber-attacks is rapidly changing. The possible consequence of such attacks is unknown because there is a lack of useful metrics, tools and frameworks to explain and evaluate the harm industries suffer from cyber-attacks. Cyber-attacks are not new to IoT, but as IoT will be strongly mixed in our days and communities, it is becoming important to step up and take cyber security severely. Hence, there is a real need to secure IoT, resulting in a need to comprehensively recognize the warnings and attacks on IoT infrastructure. The paper's main objective is to investigate the impact of the cyber-attacks in the common cyber framework and analyze the blockchain crypto-currency architecture to evaluate the weaknesses and safety representation. The security of cryptocurrency heavily relies on the incentive-compatible Proof of Authority (PoA) based on distributed consensus protocol; a consensus algorithm type based on the reputation of trusted parties in a blockchain network. This paper introduces Proof of Authority (PoA) based distributed consensus protocol and a novel blockchain-based decentralized federation model that embodies quality verification for cloud providers who lease computing resources from each other. Keywords: Blockchain security, Cryptocurrency, Internet of Things, Cloud service, Proof of Authority. I. INTRODUCTION The recent fast growth of the Internet of Things (IoT)[1] and its capacity to perform certain services have performed it the fastest developing technology, significantly affecting social lifestyles and business conditions. The Internet of Things has slowly infiltrated all components of human life today, including training, healthcare, and businesses, including collecting sensitive data about people and businesses, financial records transactions, product growth, and marketing. The extensive generation of associated devices within the Internet of Things has commenced high requirements for robust protection in response to the growing requirement for tens of millions or possibly billions of associated devices and offerings internationally [2]. The number of threats is increasing daily, and the attacks are increasing in scope and complexity. The number of potential attackers and the growing network size are not the most practical. Still, the equipment available to potential attackers has also become more advanced, efficient, and powerful [3]. Therefore, for the Internet of Things to achieve its full potential, it needs to be secure against threats and vulnerabilities. Security has been described as a way to protect an item from physical harm, unauthorized entry, theft, or loss, with the help of maintaining excessive confidentiality and integrity of facts about the item and establishing facts about that item. Any time. It is necessary. Today, cryptocurrency has grown a buzzword in both business and academia. As one of the common strong cryptocurrencies, Bitcoin has enjoyed significant compliance with its capital market that produced $10 billion in 2016 [4]. With a specially produced form of data storage, transactions on the Bitcoin network may wish to proceed without any service. The primary generation to make Bitcoin is the blockchain, first introduced in 2008 and executed in 2009 [5]. Blockchain can appear as a public record, and all authorized transactions are kept in the block list. This category is growing as new blocks are continually being attached to it. Asymmetric encryption and shared consensus algorithms have been implemented for user security and public ledger compatibility. The blockchain age frequently has the essential features of decentralization, resolution, anonymity, and audibility. With these trends, blockchain can significantly buy fees and improve efficiency. Blockchain can be applied for various financial contributions, including virtual property, online transfers, and shipping. Furthermore, it can also be achieved in other areas, including smart contracts [6], public contributions [7], and the Internet of Things (IoT). The transaction can be accomplished using automated miners for smart contracts as soon as the transaction is performed on the blockchain. Although blockchain technology can improve targeted Internet systems globally, it allows various challenging technical conditions. First of all, scalability is a huge challenge. The bitcoin block is now restricted to at least one megabyte, while the block is mined roughly every ten minutes. Thus, the Bitcoin network is limited to seven transaction fees based on the second and cannot handle frequent excessive trading. However, larger blocks indicate a larger storage area and slower spread within the network. This will begin to centralise, as fewer users will like to operate one of these huge blocks. Hence, trade-offs between block length https://doi.org/10.5281/zenodo.5854691 International Journal of Computer Science and Information Security (IJCSIS), Vol. 19, No. 12, December 2021 https://doi.org/10.5281/zenodo.5854691 42 https://sites.google.com/site/ijcsis/ ISSN 1947-5500