Data security is being the biggest roadblock to cloud computing since the data are complex and of varied mode. Many security methods have been implemented to overcome this issue. Cryptography is particularly advantageous since data may be viewed without authorization but not read. Before storing data in the cloud, data owners must encrypt it. This ensures the confidentiality of sensitive information stored on public cloud storage. There are several cryptographic approaches for ensuring secrecy. However, the majority of them rely on complicated mathematical computations and ratios. Recently big data and cloud computing have been used for secured data processing during the transmission of data to authorized persons. It can give more efficiency and more storage space to clients securely. Many investors and enterprises are willing to spend their data on a cloud network. A recent report announced 76900 accounts are signing in to the Facebook in a minute, 400360 videos are uploaded to YouTube in a minute, 7.2 million Google searches were updated in a minute, 3.4 million Instagram posts are uploaded [1]. The data owner will upload the data into the cloud network, where all the information from various services is stored. The owner has to encrypt the data and finally, the encrypted data has been given to the cloud network [2]. The data uploaded for each minute is 1.8 ZB, this storage has been provided by cloud service [3]. HHS-DNA is a symmetric key algorithm [4] i.e., the same key is used for encryption as well as for decryption. The idea of this technique is based upon DNA cryptographic technique [5]. According to the proposed scheme, if a data owner wants to upload the data onto the cloud, he has to encrypt the data. Even if the cloud service providers are forced to reveal the data, the data which has been encrypted cannot be read by unauthorized users. The traditional approaches like DES [6], AES, Blowfish [7], RSA [8], DNA cryptography etc. are still in operation for the real-time systems which are consuming enormous computing resources. So, it is required to develop a new cryptographic technique [9] that generates a bridge between the existing and the new technology.

The Cloud computing network has a storage mechanism to store the data in a cloud platform. Cloud computing networks consist of the data owner, data user, and mainly cloud data storage which is shown in Fig. 1. Once the cloud receives the request from the data user, the encrypted data from the owner is sent to the cloud for further processing.

When the user wants to accept the data, the user must have the Re-enc key. With the help of the Re-enc key [10], the data user can decrypt the content and view the data. The recent framework demonstrates privacy information of cloud networks and amplified input is given to the multi-fold cloud system. But the major center of this paper is to examine a component of this demonstration which could be a novel Re-enc symmetric key encryption method that has been utilized to encrypt/decrypt the [11] information. Asymmetric encryption techniques employs long keys to ensure the security which is a major drawback of it. Recent encryption techniques utilize more resources such as CPU time, storage, and power. Existing techniques need two keys for encrypt and decrypt the data. Most of the existing algorithms mainly involves complex and arduous numerical expressions. To overcome the hurdles existing in the prior research, the proposed HHS-DNA is a good contender for key encryption. Since this research paper utilizes symmetric key algorithm, it is easier for encrypting and decrypting large amount of data in lesser time. Compared with asymmetric algorithms, symmetric key algorithms provide more security in cloud data over the network. The speed of DNA cryptography is unremarkably 100 times high while compared with a computer. Also DNA needs lesser storage and can be perform using low power. This paper suggests reasonable encryption, which achieves high security over many attacks with the usage of low resources for encryption with less time complexity.

Section 2 progress with the review of the existing methodologies, its measures, and precise problem statements present in each methodology has efficiently emphasized. system model is presented in Section 3. Section 4 explains the proposed cryptographic algorithm and Section 5 has the results and discussion obtained by simulating the algorithm. Section 6 concludes the paper along with the future research direction of this paper.

Encrypting the data before uploading it onto the cloud prevents unauthorized users from accessing the data. A lot of encryption algorithms have been developed to secure data stored on the cloud. Hiding the messages in an organism is more reversible and scalable compared with other DNA techniques. Tacking of message is negligible using [12] technique, it is more suitable for secret military information. DNA cryptography-based encryption algorithm has been used in [13]. It generates encoding tables randomly which enables the system to become more secure. Using this special encoding technique, the plaintext is converted into a 7-bit character and finally a 5-bit character. The same plaintext provides different cipher text each time; hence it is a more flexible and reliable technique. The multi-fold symmetric DNA encryption key [14] enables the encryption process to transpire on the client side. The result was compared with the previous technique to prove the function of the symmetric key.

Later investigations [15,16] demonstrate that some hidden function is established for DNA. The first research on DNA hiding was achieved in 1997, in which “June 6 night: Normandy” was successfully hidden. It was accomplished by encoding the secret message by substituting three successive characters for one value. For example, Ä was represented as CGE”. Hence, a hidden secret may utilize keys as groundwork’s of PCR amplification to crack DNA microdots. At later repetitive codes are used to hide the secret message. RNA nucleotides have four distinctive sorts of nucleotides: adenine (A), guanine (G), cytosine (C), and uracil (U). Therefore, there are 4 = 64 distinctive combinations, with almost twenty essential amino acids.

The multi-fold symmetric-key cryptography technique is based upon DNA cryptography [17]. A consistent view about both data security concerns and privacy issues presented in the survey that are faced by clients in cloud storage environments has been carried out [18]. Further to study the security in a cloud network, Secure Hidden Layer (SHL) and Application Programming Interface (API) for data encryption explained in [19]. The SHL is consisting of two major modules (i) Key Management Server (KMS) and (ii) Share Holder Server (SHS) which is used for storing and sharing cryptographic keys. A server-side encryption algorithm, has been employed which is based on the asymmetric algorithm (RSA and CRT) for providing end-to-end security of multimedia data. A novel DNA-based data encryption scheme was introduced in [20] for the cloud computing environment. Here, a 1024-bit secret key is generated based on DNA computing, user’s attributes and Media Access Control (MAC) address of the user, and decimal encoding rule. American Standard Code for Information Interchange (ASCII) value, DNA bases, and complementary rule are used to generate the secret key that enables the system to protect against many security attacks.

A data security based strategy through DNA sequence by the virtue of Steganography has been employed by Raniyah Wazirali and Zenon Chaczko (2016). A new data concealing method based on DNA characteristics has been devised in the research. The encrypted image was represented by a DNA helix. Following, that DNA matrix was transformed to a QR (Quick Response) form, which has a wide range of applications. In addition, the article offers suggestions for selecting the best QR sites in order to get the rightmost position. A novel genetic algorithm-based model has been built [21]. Suyel Namasudra et al. (2017) have established a DNA based approach to overcome the time complexity in terms of data security. A lengthy 512-bit DNA based novel sequence has successfully utilized to improve data security, and it is protected from collision attacks, internal attacks, and other types of attacks. The suggested scheme is assessed in terms of both theoretical and experimental findings, which demonstrate its superiority to current schemes. In the future, an authorization mechanism might be implemented to improve security towards cybercriminals or bad users [22]. Chirakkarottu and Mathew [23] recommended a encryption method to encrypt the medical images. This paper mainly focused on providing security without minding the storage visual aspect. The images are initially re-arranged randomly and then DNA encrypt the images. Though the method provide security, the execution time is high. Balaraju and Rao [24] implemented Secure Hadoop Cluster using DNA Cryptography (SHCDNA) for securing data as a individual security that keeps the authenticated data in encrypted form. Although, SHCDNA reduces computations encryption of metadata is still questionable which is to be enhanced. Das et al. [25] explained the cryptography algorithm DNA in diverse facets like details about input and outputs and their nature. Yet a detailed implementation results are missing.

Based on the above researches reviewed, it is clear that the asymmetric key encryption algorithms take larger execution time. Moreover, the keys are larger and more complex for asymmetric encryption algorithm when compared to the symmetric encryption. Furthermore, the major drawbacks of existing techniques includes more power consumption, high storage and longer execution time. Hence, this paper presented an HHS-DNA to overcome the aforementioned hurdles. The subsequent Section 3 copes with the system model and structure.

The system model has five components such as Third-Party Examiner (TPE), Data owner (DO), Data User (DU), Trusted Privilege (TP), Cloud Service Provider (CSP). The system model for the proposed methodology is shown in Fig. 2.

The major application of the proposed methodology is to provide security for the data owner side. The data owner is responsible for making a key index and data accessing policy. Trusted privilege duty is updating, canceling and distributing the keys for the Data holder and Cloud Service Provider. The data holder is the entity that can outsource the data files. If the data holder has the key to satisfy the terms and policies, it will outsource the data files. CSP has two semi-honest entities such as Storage-CSP and decryption-CSP for storage and qualified decryption of cipher text respectively. When data outsourced requires, it updates its cipher text. The result is checked by a third party examiner either matched or not.

The proposed methodology is based on three levels as user level, security level, cloud storage level which are shown in Fig. 3. At the user level, encryption key generation and encryption processes have been done. At the security level, encrypted data has been uploaded to the cloud and the encryption process has been done based on key level management. At the same time, the receiver receives the encrypted data along with key management. The receiver decrypts the data based on their requirement.

For searching and verification Index I_n, user token (ω_ui) is used, while output access rights for decrypt the data. For (1 < i < n), many users have the right to access, hence i is defined as 1 < i < n, where n is the last user. If ( ωui=ωui′ ), the user has access rights, otherwise the user has the right to decline the access request. Fig. 4 shows the signature-based verification scheme and search methodology.

TP: The attribute authority (TP) takes input as the security algorithm β, and then it returns the master secret key MSK and the public parameter PK.

Extract: The AA enters the master secret key MSK, the public parameter PK, and a signing predicate Γ as input, this algorithm outputs the partial signing key p_sk and the user signing key u_sk.

Server: The server takes the partial signing key psk, the public parameter PK as an attribute set S and the message m as input, and returns the partial signature γ′ to the signer.

Signer (Data Signer): This algorithm takes input as the user signing key usk, the partial signature γ′, the attribute set S, the message m and the public parameter PK, and then the signer computes and outputs the signature € .

Transform: The verifier randomly selects the Transferred signature key t_k, and inputs the signature σ and the public parameter PK. This algorithm outputs the transformed signature €^ .

Server: This algorithm takes input as the transformed signature € and the public parameter PK and returns the intermediate signature €^ .

Verifier: The verifier takes input as the intermediate signature €^ , the transformation key t_k and the public parameter PK, then this algorithm outputs true or false.

In the result section, the proposed methodology is compared with the previous technique based on experimental and theoretical aspects. Computational cost and storage overhead are the parameters that are used to calculate the proposed methodology. We have compared and evaluated symmetric algorithms for different encryption and encoding techniques and came up with the conclusion that the recent encryption techniques utilize more resources such as CPU time, storage, and power. Also, HHS-DNA is a good contender for key encryption. The proposed encryption achieves high security over many attacks and usage of low resources for encryption.

In the proposed approach, a novel and unique Hybrid Helix Scuttle - Deoxyribo nucleic Acids (HHS-DNA) encryption algorithm have been proposed. HHS-DNA encryption reduces the encryption time, cipher text size and improves the throughput. The reduction of time complexity and improved data security is comprehended in the proposed strategy. The simulation contrasts with the proposed algorithm, DNA, and other previous techniques. When compared with previous techniques, there is a 45% improvement in throughput, 37% in encryption time, 54.67% cipher text size. Simulation outputs showed that the proposed HHS-DNA technique is a proficient scheme for encrypting the data in the cloud and improving data security. The relevant experimental results and foregoing analysis show that this method is of good robustness, stability, and security. The performance measures of the proposed scheme are correlated with the prior art techniques and acquired a performance improvement of 0.9% to 0.99%. Future research will be focused on reducing CPU processing time and CPU workload.