# Two-Layer Security Algorithms to Prevent Attacks on Data in Cyberspace
###### Abstract  
The ratio at which the number of users is increasing in cloud computing, the same as the number of data destruction, has doubled. Various algorithms have been designed to secure cloud servers to prevent an attacker from attacking, but they cannot protect the data. With the help of cryptography, data are converted into a format that is difficult for an attacker to understand, and these data can be broadcasted in a reliable format. If the attacker obtains access to the cryptographic algorithm, then the attacker can easily decrypt the data, but if the data are encrypted with the help of the key, it is difficult for the attacker to decrypt the data without the key. When the data are encrypted with the same key at different times, there is a possibility to obtain the actual key with the help of the Kasinski test. Different researchers have encrypted the data with the help of the same key or have developed an algorithm by combining different algorithms, which is a problem. This paper developed an efficient algorithm that cannot be broken easily. Even if an attacker obtains access to the algorithm, the attacker cannot identify the keys derived from that text, and the key only works in the text from which it is generated, which is the novelty of this paper. Data are secured in two different layers. In Layer-1, the proposed algorithm implements plaintext and a static key to obtain the encrypted text and a Vigenere key. In Layer-2, the encrypted text and the Vigenere key are implemented on the Vigenere cipher algorithm to obtain the ciphertext. At the end of the paper, a comparison of different papers is made with the proposed paper, and a conclusion is made based on different techniques and results.  
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of authentic users. Common inside attacks on cloud servers are replay attacks, phishing, and man-in-the-middle attacks [4]. When an attacker enters the cloud server through any mechanism, the first attempt of an attacker is to use such mechanisms, with the help of which data can be misused, or malicious data can be stored in place of the original data [5]. Whenever the data are uploaded to the cloud server, they can be attacked and accessed, but despite accessing the data, the attacker cannot decrypt the data. Data decryption can only be possible when implementing the same mechanism designed to decrypt the data. If the attacker deploys the decryption mechanism, to decrypt the cipher data, it is also necessary to have the key that was used while encrypting the data, which is a problem. Using the same algorithm and key is necessary to decrypt the data. If neither of the two are available, data decryption cannot be possible.  
Different researchers have developed different algorithms to protect the cloud server from external attacks, with the help of which intruders can be detected in cyberspace and access to the cloud server can be prevented. However, when an authentic user on the cloud server attempts to destroy the data, it is challenging to detect such a user and prevent the data from being misused in cyberspace. When any malicious activity is done in cyberspace, whether it is done internally or externally, such activities and intruders can be blocked [6] and they can be prevented from doing harmful activities, but the data cannot be saved. Cryptography is the best solution to solve this problem [7].