ENHANCED VIGENERE CIPHER ALGORITHM FOR IMPROVED CRYPTOGRAPHIC SECURITY

The subsequent stage of communication is characterized by the Internet of Things (IoT). Through the implementation of IoT, tangible objects are rendered capable of generating, receiving, and disseminating data via the internet. These physical entities are interconnected and are able to exchange substantial volumes of data with other digital components autonomously, without necessitating human intervention. Presently, one of the critical challenges that threaten the integrity of "Internet of Things" devices pertains to the security and privacy of the information that is gathered and transmitted, which is often intimately associated with the personal lives of the users. Various encryption methodologies are employed to safeguard data from diverse user access. Among these, encryption stands out as one of the most efficacious techniques for the secure transmission of data across communication networks. The process of encryption involves the application of a cipher algorithm to transform readable data (designated as plaintext) into an unintelligible format (referred to as cipher text). The Vigenère cipher represents a method for encrypting alphabetic text utilizing a series of distinct Caesar ciphers, which are determined by the characters of a specified keyword. Numerous encryption algorithms are currently prevalent in computational practices. This particular form of polyalphabetic substitution is considered relatively straightforward. For many generations, the Vigenère cipher was regarded as secure; however, its vulnerabilities were later identified. This paper proposes an innovative encryption method aimed at facilitating secure and safe data communication. The Vigenère cipher has been augmented and modified to incorporate extended ASCII code in lieu of solely relying on ASCII code, in addition to the inclusion of alphabets, numerals, and symbols. Furthermore, a swapping operation has been executed. These enhancements are intended to elevate the algorithm's complexity and attain a heightened level of encryption. Additionally, this modification serves to strengthen the security of the Vigenère cipher.