Recently, two chaotic image encryption schemes have been proposed, in which shuffling the positions and changing the grey values of image pixels are combined. This paper provides the chosen plaintext attack to recover...Recently, two chaotic image encryption schemes have been proposed, in which shuffling the positions and changing the grey values of image pixels are combined. This paper provides the chosen plaintext attack to recover the corresponding plaintext of a given ciphertext. Furthermore, it points out that the two schemes are not sufficiently sensitive to small changes of the plaintext. Based on the given analysis, it proposes an improved algorithm which includes two rounds of substitution and one round of permutation to strengthen the overall performance.展开更多
A digital image encryption scheme using chaotic map lattices has been proposed recently. In this paper, two fatal flaws of the cryptosystem are pointed out. According to these two drawbacks, cryptanalysts could recove...A digital image encryption scheme using chaotic map lattices has been proposed recently. In this paper, two fatal flaws of the cryptosystem are pointed out. According to these two drawbacks, cryptanalysts could recover the plaintext by applying the chosen plaintext attack. Therefore, the proposed cryptosystem is not secure enough to be used in the image transmission system. Experimental results show the feasibility of the attack. As a result, we make some improvements to the encryption scheme, which can completely resist our chosen plaintext attack.展开更多
In this article we present a lattice attack done on a NTRU-like scheme introduced by Verkhovsky in [1]. We show how, based on the relation between the public and private key, we can construct an attack which allows an...In this article we present a lattice attack done on a NTRU-like scheme introduced by Verkhovsky in [1]. We show how, based on the relation between the public and private key, we can construct an attack which allows any passive adversary to decrypt the encrypted messages. We explain, step by step, how an attacker can construct an equivalent private key and guess what the original plaintext was. Our attack is efficient and provides good experimental results.展开更多
With the increasing interconnection of computer networks and sophistication of cyber-attacks, Cryptography is one way to make sure that confidentiality, authentication, integrity, availability, and identification of d...With the increasing interconnection of computer networks and sophistication of cyber-attacks, Cryptography is one way to make sure that confidentiality, authentication, integrity, availability, and identification of data user can be maintained as well as security and privacy of data provided to the user. Symmetric key cryptography is a part of the cryptographic technique which ensures high security and confidentiality of data transmitted through the communication channel using a common key for both encryption and decryption. In this paper I have analyzed comparative encryption algorithms in performance, three most useful algorithms: Data Encryption Standard (DES), Triple DES (3DES) also known as Triple Data Encryption Algorithm (TDEA), and Advanced Encryption Standard (AES). They have been analyzed on their ability to secure data, time taken to encrypt data and throughput the algorithm requires. The performance of different algorithms differs according to the inputs.展开更多
An image block encryption scheme based on spatiotemporal chaos has been proposed recently. In this paper, we analyse the security weakness of the proposal. The main problem of the original scheme is that the generated...An image block encryption scheme based on spatiotemporal chaos has been proposed recently. In this paper, we analyse the security weakness of the proposal. The main problem of the original scheme is that the generated keystream remains unchanged for encrypting every image. Based on the flaws, we demonstrate a chosen plaintext attack for revealing the equivalent keys with only 6 pairs of plaintext/ciphertext used. Finally, experimental results show the validity of our attack.展开更多
In this paper an encryption-decryption algorithm based on two moduli is described: one in the real field of integers and another in the field of complex integers. Also the proper selection of cryptographic system para...In this paper an encryption-decryption algorithm based on two moduli is described: one in the real field of integers and another in the field of complex integers. Also the proper selection of cryptographic system parameters is described. Several numeric illustrations explain step-by-step how to precondition a plaintext, how to select secret control parameters, how to ensure feasibility of all private keys and how to avoid ambiguity in the process of information recovery. The proposed cryptographic system is faster than most of known public key cryptosystems, since it requires a small number of multiplications and additions, and does not require exponentiations for its implementation.展开更多
This paper proposes three different chaotic encryption methods using 1-D chaotic map known as Logistic map named as Logistic, NLFSR and Modified NLFSR according to the name of chaotic map and non-linear function invol...This paper proposes three different chaotic encryption methods using 1-D chaotic map known as Logistic map named as Logistic, NLFSR and Modified NLFSR according to the name of chaotic map and non-linear function involved in the scheme. The designed schemes have been crypt analyzed for five different methods for testing its strength. Cryptanalysis has been performed for various texts using various keys selected from domain of key space. Logistic and NLFSR methods are found to resist known plaintext attack for available first two characters of plaintext. Plaintext sensitivity of both methods is within small range along with medium key sensitivity. Identifiability for keys of first two of the scheme has not been derived concluding that methods may prove to be weak against brute-force attack. In the last modified scheme avalanche effect found to be improved compared to the previous ones and method is found to resist brute-force attack as it derives the conclusion for identifiability.展开更多
In this paper, we present one method to attack on the GMR-2 algorithm used in satellite phone under the chosen-plaintexts. First using the relationship of the rows of the two s-boxes and outputs of the F coordinate, w...In this paper, we present one method to attack on the GMR-2 algorithm used in satellite phone under the chosen-plaintexts. First using the relationship of the rows of the two s-boxes and outputs of the F coordinate, we attack on the GMR-2 algorithm. Then we deduce the happening probability of read-collision, and analyze its mathematical expectation. Finally, combining with the read-collision, we present an improved method to attack on the GMR-2 algorithm. The research results show that the complexity of the improved algorithm is about 220, and the session key Kc can be recovered in about 0.3 seconds. Compared with the available method, our method takes less time than the guess-and-decide attack method which is 700 s.展开更多
基金Project supported by the Natural Science Foundation of Shandong Province, China (Grant No Y2007G43)
文摘Recently, two chaotic image encryption schemes have been proposed, in which shuffling the positions and changing the grey values of image pixels are combined. This paper provides the chosen plaintext attack to recover the corresponding plaintext of a given ciphertext. Furthermore, it points out that the two schemes are not sufficiently sensitive to small changes of the plaintext. Based on the given analysis, it proposes an improved algorithm which includes two rounds of substitution and one round of permutation to strengthen the overall performance.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61173183, 60973152, and 60573172)the Doctoral Program Foundation of Institution of Higher Education of China (Grant No. 20070141014)+2 种基金the Program for Excellent Talents in Universities of Liaoning Province, China (Grant No. LR2012003)the Natural Science Foundation of Liaoning Province, China (Grant No. 20082165)the Fundamental Research Funds for the Central Universities of China (Grant No. DUT12JB06)
文摘A digital image encryption scheme using chaotic map lattices has been proposed recently. In this paper, two fatal flaws of the cryptosystem are pointed out. According to these two drawbacks, cryptanalysts could recover the plaintext by applying the chosen plaintext attack. Therefore, the proposed cryptosystem is not secure enough to be used in the image transmission system. Experimental results show the feasibility of the attack. As a result, we make some improvements to the encryption scheme, which can completely resist our chosen plaintext attack.
文摘In this article we present a lattice attack done on a NTRU-like scheme introduced by Verkhovsky in [1]. We show how, based on the relation between the public and private key, we can construct an attack which allows any passive adversary to decrypt the encrypted messages. We explain, step by step, how an attacker can construct an equivalent private key and guess what the original plaintext was. Our attack is efficient and provides good experimental results.
文摘With the increasing interconnection of computer networks and sophistication of cyber-attacks, Cryptography is one way to make sure that confidentiality, authentication, integrity, availability, and identification of data user can be maintained as well as security and privacy of data provided to the user. Symmetric key cryptography is a part of the cryptographic technique which ensures high security and confidentiality of data transmitted through the communication channel using a common key for both encryption and decryption. In this paper I have analyzed comparative encryption algorithms in performance, three most useful algorithms: Data Encryption Standard (DES), Triple DES (3DES) also known as Triple Data Encryption Algorithm (TDEA), and Advanced Encryption Standard (AES). They have been analyzed on their ability to secure data, time taken to encrypt data and throughput the algorithm requires. The performance of different algorithms differs according to the inputs.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61173183,60973152,and 60573172)the Doctoral Program Foundation of Institution of Higher Education of China (Grant No. 20070141014)the Natural Science Foundation of Liaoning Province,China (Grant No. 20082165)
文摘An image block encryption scheme based on spatiotemporal chaos has been proposed recently. In this paper, we analyse the security weakness of the proposal. The main problem of the original scheme is that the generated keystream remains unchanged for encrypting every image. Based on the flaws, we demonstrate a chosen plaintext attack for revealing the equivalent keys with only 6 pairs of plaintext/ciphertext used. Finally, experimental results show the validity of our attack.
文摘In this paper an encryption-decryption algorithm based on two moduli is described: one in the real field of integers and another in the field of complex integers. Also the proper selection of cryptographic system parameters is described. Several numeric illustrations explain step-by-step how to precondition a plaintext, how to select secret control parameters, how to ensure feasibility of all private keys and how to avoid ambiguity in the process of information recovery. The proposed cryptographic system is faster than most of known public key cryptosystems, since it requires a small number of multiplications and additions, and does not require exponentiations for its implementation.
文摘This paper proposes three different chaotic encryption methods using 1-D chaotic map known as Logistic map named as Logistic, NLFSR and Modified NLFSR according to the name of chaotic map and non-linear function involved in the scheme. The designed schemes have been crypt analyzed for five different methods for testing its strength. Cryptanalysis has been performed for various texts using various keys selected from domain of key space. Logistic and NLFSR methods are found to resist known plaintext attack for available first two characters of plaintext. Plaintext sensitivity of both methods is within small range along with medium key sensitivity. Identifiability for keys of first two of the scheme has not been derived concluding that methods may prove to be weak against brute-force attack. In the last modified scheme avalanche effect found to be improved compared to the previous ones and method is found to resist brute-force attack as it derives the conclusion for identifiability.
基金supported by China Scholarship Council under Grant No.201506965088
文摘In this paper, we present one method to attack on the GMR-2 algorithm used in satellite phone under the chosen-plaintexts. First using the relationship of the rows of the two s-boxes and outputs of the F coordinate, we attack on the GMR-2 algorithm. Then we deduce the happening probability of read-collision, and analyze its mathematical expectation. Finally, combining with the read-collision, we present an improved method to attack on the GMR-2 algorithm. The research results show that the complexity of the improved algorithm is about 220, and the session key Kc can be recovered in about 0.3 seconds. Compared with the available method, our method takes less time than the guess-and-decide attack method which is 700 s.
