Based on some analyses of existing chaotic image encryption frameworks and a new designed three-dimensional improved logistic chaotic map(3D-ILM),an asymmetric image encryption algorithm using public-key Rivest–Shami...Based on some analyses of existing chaotic image encryption frameworks and a new designed three-dimensional improved logistic chaotic map(3D-ILM),an asymmetric image encryption algorithm using public-key Rivest–Shamir–Adleman(RSA)is presented in this paper.In the first stage,a new 3D-ILM is proposed to enhance the chaotic behavior considering analysis of time sequence,Lyapunov exponent,and Shannon entropy.In the second stage,combined with the public key RSA algorithm,a new key acquisition mathematical model(MKA)is constructed to obtain the initial keys for the 3D-ILM.Consequently,the key stream can be produced depending on the plain image for a higher security.Moreover,a novel process model(NPM)for the input of the 3D-ILM is built,which is built to improve the distribution uniformity of the chaotic sequence.In the third stage,to encrypt the plain image,a pre-process by exclusive OR(XOR)operation with a random matrix is applied.Then,the pre-processed image is performed by a permutation for rows,a downward modulo function for adjacent pixels,a permutation for columns,a forward direction XOR addition-modulo diffusion,and a backward direction XOR addition-modulo diffusion to achieve the final cipher image.Moreover,experiments show that the the proposed algorithm has a better performance.Especially,the number of pixels change rate(NPCR)is close to ideal case 99.6094%,with the unified average changing intensity(UACI)close to 33.4634%,and the information entropy(IE)close to 8.展开更多
The study on design and implementation of end to end encrypted Short Message Service (SMS) using hybrid cipher algorithm is motivated by high rate of insecurity of data observed during Short Message Service (SMS) on M...The study on design and implementation of end to end encrypted Short Message Service (SMS) using hybrid cipher algorithm is motivated by high rate of insecurity of data observed during Short Message Service (SMS) on Mobile devices. SMS messages are one of the popular ways of communication. The aim therefore is to design a software for end to end encryption short message service (SMS) that can conceal message while on transit to another mobile device using Hybrid Cipher Algorithm on Android Operating System and implement it for security of mobile SMS. Hybrid encryption incorporates a combination of asymmetric and symmetric encryption to benefit from the strengths of each form of encryption. Various encryption algorithms have been discussed. Secondary sources were employed in gathering useful data. In this research work three methodologies are employed—Structured System Analysis Design Methodology (SSADM), Object Oriented Analysis Design Methodology (OOADM) and prototyping. With the help of the three cryptographic algorithms employed—Message digest 5 (MD5), Blowfish and Rivest-Shamir Adleman (RSA);integrity, confidentiality, authentication and security of messages were achieved. The messages encrypted by developed application are also resistant to brute force attack. The implementing programs were coded in Java.展开更多
基金the National Natural Science Foundation of China(Grant No.61972103)the Natural Science Foundation of Guangdong Province of China(Grant No.2023A1515011207)+3 种基金the Special Project in Key Area of General University in Guangdong Province of China(Grant No.2020ZDZX3064)the Characteristic Innovation Project of General University in Guangdong Province of China(Grant No.2022KTSCX051)the Postgraduate Education Innovation Project of Guangdong Ocean University of China(Grant No.202263)the Foundation of Guangdong Provincial Engineering and Technology Research Center of Far Sea Fisheries Management and Fishing of South China Sea.
文摘Based on some analyses of existing chaotic image encryption frameworks and a new designed three-dimensional improved logistic chaotic map(3D-ILM),an asymmetric image encryption algorithm using public-key Rivest–Shamir–Adleman(RSA)is presented in this paper.In the first stage,a new 3D-ILM is proposed to enhance the chaotic behavior considering analysis of time sequence,Lyapunov exponent,and Shannon entropy.In the second stage,combined with the public key RSA algorithm,a new key acquisition mathematical model(MKA)is constructed to obtain the initial keys for the 3D-ILM.Consequently,the key stream can be produced depending on the plain image for a higher security.Moreover,a novel process model(NPM)for the input of the 3D-ILM is built,which is built to improve the distribution uniformity of the chaotic sequence.In the third stage,to encrypt the plain image,a pre-process by exclusive OR(XOR)operation with a random matrix is applied.Then,the pre-processed image is performed by a permutation for rows,a downward modulo function for adjacent pixels,a permutation for columns,a forward direction XOR addition-modulo diffusion,and a backward direction XOR addition-modulo diffusion to achieve the final cipher image.Moreover,experiments show that the the proposed algorithm has a better performance.Especially,the number of pixels change rate(NPCR)is close to ideal case 99.6094%,with the unified average changing intensity(UACI)close to 33.4634%,and the information entropy(IE)close to 8.
文摘The study on design and implementation of end to end encrypted Short Message Service (SMS) using hybrid cipher algorithm is motivated by high rate of insecurity of data observed during Short Message Service (SMS) on Mobile devices. SMS messages are one of the popular ways of communication. The aim therefore is to design a software for end to end encryption short message service (SMS) that can conceal message while on transit to another mobile device using Hybrid Cipher Algorithm on Android Operating System and implement it for security of mobile SMS. Hybrid encryption incorporates a combination of asymmetric and symmetric encryption to benefit from the strengths of each form of encryption. Various encryption algorithms have been discussed. Secondary sources were employed in gathering useful data. In this research work three methodologies are employed—Structured System Analysis Design Methodology (SSADM), Object Oriented Analysis Design Methodology (OOADM) and prototyping. With the help of the three cryptographic algorithms employed—Message digest 5 (MD5), Blowfish and Rivest-Shamir Adleman (RSA);integrity, confidentiality, authentication and security of messages were achieved. The messages encrypted by developed application are also resistant to brute force attack. The implementing programs were coded in Java.
