A Solution to Text Hiding in Media with Hybrid Gravity Search Algorithm and Transposition Scheme Trong-The Nguyen1,2 , Truong-Giang Ngo3(B) , Thi-Thanh-Tan Nguyen4 , Chi-Kien Tran5 , and Ngoc-Cuong Nguyen6 School of Computer Science and Mathematics, Fujian University of Technology, Fujian, China University of Management, and Technology, Haiphong, Vietnam Faculty of Computer Science and Engineering, Thuyloi University, 175 Tay Son, Dong Da, Hanoi, Vietnam giangnt@tlu.edu.vn Information Technology Faculty, Electric Power University, Hanoi, Vietnam Hanoi University of Industry, Hanoi, Vietnam Department of Cyber Security and Counter High-Tech Crime, Ministry of Public Security, Hanoi, Vietnam Abstract This paper suggests a new solution to conceal text messages in media by hybridizing a meta-heuristic algorithm of the Gravity search algorithm (GSA) and transposition method Several stages are implemented, namely the concealment stage, extract stage, and evaluation metrics, whereas cover text and message text are split into blocks, and each block contains one letter, relying on the fitness value of related notes both of secret information and cover message The best positions of the letters are taken optimization by the adjusting GSA that is used to hide the confidential message The steganography process is then carried out through the transposition process between the secret and cover message While in the extraction stage, the fitness value of steganography message letters is found by using GSA to determine the positions that represent the secret letters Experimental results of the proposed scheme are compared with the other in the literature which shows that the proposed approach presents robust security, provides high capacity and resistance against several steganalysis attacks Keywords: Gravity search algorithm · Information hiding · Transposition scheme Introduction There is no doubt that steganography has become a critical security science that is widely applied in communication and transactions in everyday life [1] The transmission of a message on the Internet, e.g., for communication or transactions has to count on some issues such as data security, copyright control Secret communication systems for safety information and tips are needed [2] Data hiding attempts to conceal hidden © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2021 J.-S Pan et al (eds.), Advances in Intelligent Information Hiding and Multimedia Signal Processing, Smart Innovation, Systems and Technologies 212, https://doi.org/10.1007/978-981-33-6757-9_54 A Solution to Text Hiding in Media with Hybrid Gravity … 435 information in media such as a form that can not be seen, and the covering mask is complicated to decode [3] The hiding information technique usually includes several subdisciplines within the field of information security, such as watermarking, digital signatures, steganography, and cryptography Each of these methods has its function, with benefits and drawbacks Watermarking is commonly used to safeguard the copyright, and digital signatures are frequently used to protect digital signatures [4], while steganography and cryptography are widely used to encrypt digital messages [5] The cryptography scrambles the letters so that it is not easily understandable Steganography and cryptography diverge Cryptography aims to provide encrypted communication by transforming the data into a shape that an eavesdropper can not easily comprehend The practice of covering text in another medium is referred to as a steganography intended to insure contact This means unauthorized users are unable to get the privately used hidden message [6] As stated, text steganography was considered to be the most challenging technique compared to audio and picture one due to inadequate redundant data, popular in other carriers, rendering most of its technology with inadequate capability and security [7] The right to add hidden data to protect archives, though, relies on the existence of redundant or irrelevant information inside them The characteristics of a cover file which is altered, exploited, or updated during the embedding process will remain invisible to unauthorized users [8] To cover text-in-text communications, including format based, random and mathematical generations, and linguistic approaches, three major categories are employed Format based is the covering message that in the case of the terms and phrases will not be changed; changes will only be made to the gaps between terms, lines, or/and paragraphs using special characters, i.e., white space steganography The cover text message is automatically generated by random and mathematical generation methods; it does not require an existing cover code Throughout the creation process, a hidden message is used for the created cover message [9] The linguistic approach is used to conceal a message in another message based on the cover message’s linguistic structure with the punctuation marks or the semantic terms as a way to hide the letter, letter, which has two key forms which are linguistic structure and semantic approach The techniques have drawbacks, such as the data size depends on the number of the cover message’s punctuation marks and failed to protect the message sent when the outsider attempts to find the original message by swapping each word to the original one using the semantic algorithms [10] One of the promising ways to solve complex problems is the metaheuristic algorithm [11] Many metaheuristics are built on the basis of natural phenomenal inspirations such as synthetic annealing (SA) [12], genetic algorithm (GA) [13], and particle swarm optimization (PSO) [14] The Gravity Search Algorithm (GSA) [15] is a recent metaheuristic algorithm which is inspired by the actual gravity phenomena This paper introduces a new solution for text steganography through the combination of GSA and the transposition process The solution suggested seeks to solve the aforementioned inconveniences of previous approaches 436 T.-T Nguyen et al Gravity Search Algorithm (GSA) GSA algorithm is taken inspiration from the physical phenomenon of gravity, in which planets interact through the action of gravity [15] The planets with large mass are a more attractive force The planets with a small mass approach it and the planets with large mass occupy the central position, which is, the optimal position seeks, which is the search principle of the GSA algorithm The GSA algorithm will communicate with each other, to guide planets to the optimal worlds The mathematical model of the GSA algorithm can be expressed by a series of expressions as follows Xid (t + 1) = Xid (t) + Vel id (t + 1) (1) where Xid (t), and Vel di (t), respectively, represent the position, velocity The Velocity Vel is calculated as follows Vel id (t + 1) = rand · Vel id (t) + aid (t) (2) where aid (t) represent acceleration, and be expressed as follows aid (t + 1) = Fid (t)/Mid (t) (3) where Fid (t), and Mid (t), respectively, represent gravitational force, and position of the ith planet in the d—dimension during the tth iteration The magnitude of the resultant force and the mass of inertia The calculation mathematical of inertia mass force is expressed in the gravity inspiration as follows The calculation of the resultant force is expressed as follows Fijd (t) = G(t) · Mi (t) · Mj (t) · Xjd (t) − Xid (t) Rij (t) + ε (4) N Fid (t) randj · Fijd (t) = (5) j=1,j=i In the formula: N is the total number of particles; Fijd (t) represents the gravitational force of particle j to particle i; randj is a random number of [0, 1]; Rij (t) is the Euclidean distance between particle i and particle j; ε is a constant with a small value; G(t) is the gravitational constant The calculation formula is given as follows G(t) = G0 · exp(−α · t/ max t) (6) Among them: G0 and α are constants; t is the current number of iterations; maxt is the maximum number of iterations.The inertial mass of the particles in Eq (4) can be obtained based on the following equations: mi (t) = fiti (t) − worst(t) best(t) − worst(t) (7) A Solution to Text Hiding in Media with Hybrid Gravity … 437 N Mi (t) = mi (t) mj (t) (8) j=1 where fiti (t) represents the fitness value of the ith particle at the tth iteration For the image multi-threshold segmentation problem for which the maximum value is obtained, best(t) and worst (t) are obtained based on following as best(t) = max fitj (t), j ∈ {1, 2, , N } (9) worst(t) = fitj (t), j ∈ {1, 2, , N } (10) A Solution to Conceal Text Messages Steganography’s main task is to thwart the unauthorized user from knowing that something is hidden even if he/she can get the stego cover We use the invisible character structure (white space) to protect text in the text, where the secret message is hidden in the cover medium’s white space position, the results show that the method is highly confidential because it uses functional complexity to avoid unauthorized users The limitation of this technique is that the binary string length must be less than or equal to the number of spaces for words This paper proposed a rule-based steganography technique for the selection of privacy channels in the spatial domain Steganography is commonly used in Internet communication because of its utility, where it is not encoding information but rather hiding The presence of it that makes the hacker’s task difficult Any characteristics in a production framework are as follows Using the method of transposition between the secret message and the cover message, that means that there is no addition, deletion, or change By applying GSA, the best locations of the letters in the cover medium are optimized, and the method is used for combining with hiding processing in the transposition The new scheme has high flexibility relative to test results and improves robustness 3.1 Objective Function The objective function is as fitness function would be drawn the relationship between the secret message and cover medium, i.e., message Let A(i) be the ASCII code represents for that letter; S(i) be the sequence of the letter represents in the set of letters; L(i) be the location of letters and the rand is random value distribution in the range [0,1] The relationship of each character in the cover message and secret message that uses find out the fitness value in the process of steganography by the planets of GSA, where fitness considered one of the important stages in the GSA algorithm The objective function is expressed as follows Fitness(i) = A(i) ∗ S(i) ∗ rand iL (11) where A and S are ASCII character codes and the sequence of the letter in the set of characters; L is the location of letters, and the rand is random distribution ∈ [0–1] 438 T.-T Nguyen et al 3.2 The System Design The design of the proposed scheme consists of three phases of steganography processing, such as embedding, extracting process, and evaluating criterion Figure shows a flowchart of the design of the proposed scheme The phases of embedding, obtaining process, and evaluating tests are expressed as follows Fig Flowchart of the design of the proposed scheme (embedding, extracting process, and evaluating criterion) • Embedding process—the positions that are used to hiding that are determined by adjusting GSA, as well as the process of embedding text in the text by the transposition method is achieved • Extracting process—the extraction process includes extract the secret message from the stego message by applying GSA • Evaluation criterion—comparing the cover message and stego message, if there is no difference between them, then the steganography process will be transporting a letter with another letter Therefore, an unauthorized user can’t suspect that something is hidden in the stego message even if it uses all statistical meatuses and detection techniques or makes a comparison between them through the see or by size Experimental Results The obtained results of the proposed scheme of (GSA) [15]are compared with the simulated annealing (SA)[12], genetic algorithm (GA)[13], and particle swarm optimization (PSO)[14] methods for hiding information respectively The number of planets as agents A Solution to Text Hiding in Media with Hybrid Gravity … 439 of the algorithms is set to N equal to 60, and the maximum number of iterations is Maxgen is set to 1000; the gravitational beginning G0 and the step factor α are set to 10 and 0.1, respectively The other parameters set for the algorithms listed as follows: c1 = 0.5, c2 = 1.5, inertia weight ω = 1.2, particle velocity V ∈ [−5, 5], mutation rate pr is set 0.05, and cross-rate cr set to 0.6 Figure shows an example of the secret message, and the secret message is used for testing the proposed scheme.A secret message with size 13.9 KB that is used to be hidden into the secret message The secret message consists of words with 18 characters Table listed the fitness calculated for each letter by using Eq (8) The cover message with a size of 19.2 KB, which consists of 114 words with 683 character Fig An example of the secret message and the secret message Table Initialization of fitness values for the secret message Sequence No Characters Fitness value Sequence No Characters Fitness value A 0.436 10 Y 0.931 N 0.910 11 S 0.562 N 0.910 13 E 0.672 I 0.293 13 c 0.155 N 0.910 14 u 0.091 H 0.672 15 r 0.756 i 0.293 16 i 0.293 s 0.562 17 t 0.290 m 0.435 18 y 0.931 Several parameters are used to measure the experimental results that are listed as follows: Entropy, Energy, Variance, Squared Pearson Correlation Coefficient (SPCC), Structural Similarity Index Metric (SSIM), Signal to Noise Ratio (SNR), Average, 440 T.-T Nguyen et al Euclidian distance, Chi-square [16] Table depicts the comparison of obtained values between the cover message and secret message by applying calculations of several measurements Table Comparison of obtained values between the cover message and stego message by using several measurements Parameters of measurements Derivative rate Cover message Secret message Entropy 0.02 4.1177 4.1175 Average 0.09 108.7754 108.7745 Energy 0.02 2.5617 2.5615 Variance 0.02 98.5799 98.5797 SNR 0.02 1.9556 1.9554 Chi-square, p 0.02 0.0977 0.0975 SSIM 0.02 0.9977 0.9975 SPCC 0.02 0.9977 0.9975 Euclidian distance 0.00 0.0001 0.0001 Figure shows the comparison of the obtained results of the proposed scheme of GSA with the SA, GA, and PSO methods for hiding information, respectively Subfigures: (a) Comparison of the received error values; (b) Comparison of the converge rates It is clearly seen that the obtained results of the proposed scheme of GSA for information hiding are better than the other methods in terms of converge rate and accuracy rate (a) Comparison of converge rates (b) Comparison of obtained error values Fig A comparison of the obtained results of the proposed scheme of GSA with the SA, GA, and PSO methods for hiding information, respectively Subfigures: a Comparison of obtained error values; b Comparison of converge rates A Solution to Text Hiding in Media with Hybrid Gravity … 441 Conclusion In this paper, we presented a solution to improving the scheme of hiding messages in text messages by hybridizing the gravity search algorithm (GSA) and the transposition scheme Several stages are implemented, namely the hiding stage, extract stage, and evaluation metrics Both cover text and message text are split into blocks, and each block contains one character according to its fitness value of related notes both of secret information and cover message The GSA adjusting to hide the confidential message takes optimization of the character’s best positions The process of steganography is then carried out through the process of transposing between the message of secrecy and cover The fitness value of steganography message letters is found while in the extraction stage by using GSA to determine the positions which represent the secret letters In the literature, experimental findings of the proposed scheme are compared with the other show that the proposed solution offers robust protection, provides high potential, and resistance against multiple steganalysis attacks References Narayana, V.L., et al.: Different techniques for hiding the text information using text steganography techniques: a survey, vol 23, p 115 (2018) Mahajan, M., Kaur, N.: Adaptive steganography: a survey of recent statistical aware steganography techniques Int J Comput Netw Inf Secur 4, 76 (2012) Nguyen, T.-T., et al.: A data hiding approach based on reference-affected matrix BT— Advances in Intelligent Information Hiding and Multimedia Signal Processing (2020) Roy, A., Karforma, S.: A Survey on digital signatures and its applications J Comput Inf Technol 3, 45–69 (2012) Wu, T.-Y., Tseng, Y.-M.: Publicly verifiable multi-secret sharing scheme from bilinear pairings IET Inf Secur 7, 239–246 (2013) Wu, T.-Y., et al.: A revocable ID-based authenticated group key exchange protocol with resistant to malicious participants Comput Networks 56, 2994–3006 (2012) Wu, T.-Y., Lin, J.C.-W., Chen, C.-M., Tseng, Y.-M., Frnda, J., Sevcik, L., Voznak, M.: A brief review of revocable ID-based public key cryptosystem Perspect Sci 7, 81–86 (2016) Chen, C.-M., Xu, L., Wu, T.-Y., Li, C.-R.: On the security of a chaotic maps-based three-party authenticated key agreement protocol J Netw Intell., 61–65 (2016) Wu, T.-Y., et al.: On the security of a certificateless searchable public key encryption scheme In: International Conference on Genetic and Evolutionary Computing, pp 113–119 (2016) 10 Sharma, S., et al : Analysis of different text steganography techniques: a survey In: 2016 Second International Conference on Computer Intelligence & Communications Technology (CICT), pp 130–133 IEEE (2016) 11 Nguyen, T.T., et al.: An improved flower pollination algorithm for optimizing layouts of nodes in wireless sensor network IEEE Access 7, 75985–75998 (2019) 12 Liu, G., Dai, Y., Wang, J., Wang, Z.: Secure data hiding algorithm based on simulated annealing Opt Precis Eng 5, 200–209 (2007) 13 Wang, S., Yang, B., Niu, X.: A secure steganography method based on genetic algorithm J Inf Hiding Multimed Signal Process 1, 28–35 (2010) 14 Guo, Y., Kong, X., You, X.: Secure steganography based on binary particle swarm optimization J Electron 26, 285–288 (2009) 442 T.-T Nguyen et al 15 Rashedi, E., Nezamabadi-pour, H., Saryazdi, S.: GSA: a gravitational search algorithm Inf Sci (Ny) 179, 2232–2248 (2009) https://doi.org/10.1016/j.ins.2009.03.004 16 Subhedar, M.S., Mankar, V.H.: Current status and key issues in image steganography: a survey Comput Sci Rev 13, 95–113 (2014) .. .A Solution to Text Hiding in Media with Hybrid Gravity … 435 information in media such as a form that can not be seen, and the covering mask is complicated to decode [3] The hiding information... (GSA) and the transposition scheme Several stages are implemented, namely the hiding stage, extract stage, and evaluation metrics Both cover text and message text are split into blocks, and each... between terms, lines, or /and paragraphs using special characters, i.e., white space steganography The cover text message is automatically generated by random and mathematical generation methods;