## 2 Privacy and Security Issues  
IoT-based innovative applications took the place of traditional applications with the advancement of IoT technology. Many jobs have been undertaken concerning IoT structure and protocols of IoT-based products. The privacy and security problems still need to be focused on IoT approaches to face security and privacy concerns, as discussed in [3]. The device has limitations, and a new attack paradigm for IoT-based applications is outlined layer-wise. The gadget has limits, and a further assault paradigm for IoT-based applications is outlined layer-wise. IoT apps are built using a structure described in [4], where the inventors identify eight possible frameworks for constructing applications and their security and privacy challenges. Security and privacy issues, such as authentication and data protection, are the most challenging aspects of designing IoT applications, according to [5; 6], where the authors show how blockchain, cloud computing, and device understanding might be used to solve the problem. There are three layers to the IoT infrastructure: physical, network, and application. Each of these tiers has a security vulnerability. Security Challenges in IoT  
The security problems of IoT applications are discussed in this section. Most IoT applications deal with the physical, network, and application layers that make up a three-layer architecture level of application. The gateway connects the components in the physical layer. The capabilities of the physical gadget are restricted, and it is vulnerable to an attacker. Figure 1: Flow diagram of the security process. It is not recommended to change the overall situation if a physical element is compromised. The thief was the one who stole it. When each layer is available, the system must deal with the issue of cybersecurity. **Node capture attacks**: IoT applications place intelligent devices in various locations to connect to the network, making it possible for attackers to grab or replace them with an unsuitable device. It is hard to distinguish between the brilliance and the false nodes in this kind of physical assault. The attacker may obtain crucial details about the software through this attack. The network has to be secured against attacks of this kind. **Replay attacks:** The perpetrators broadcast identical information to the network after intercepting it on telecommunications. An attacker may seize control of intelligent gadgets in an \"IoT infrastructure\" and transmit data as if they were a legal network node. Attacks from the side channel: In side-channel attacks, the attacker tries to decipher the ciphertext to retrieve the plaintext. Gaining the key through a time constant is crucial since most encryption methods employ key exchanges for encryption and decryption. **False data injection:** To read environmental data, smart devices or sensors are deployed in various places. Sensors and intelligent devices can gather and transmit data to the following layer. Smart gadgets are susceptible to attackers due to their resource restrictions. The attacker tries to intercept the gadget or extract the value from an unprotected communication channel to introduce fake data into the network. **Eavesdropping:** An eavesdropping attack takes place in an IoT environment where compromised smart devices are reading one another's messages because the communication link is not protected. In a passive assault, the advertiser collects information from an unreliable communication route. **Spoofing:** The attacker attempts to obtain access to the network layer of smart devices, then, after doing so, pretends to be a network node and sends false signals across the network. **Denial-of-service (DoS) attacks:** Cyber-attacker uses the system's permission to send a large amount of data to a server in an attempt to overload it; as a result, it will be unable to use the entire amount of bandwidth and resources available, costing the victim a significant amount of money.