14 results about "Chosen-plaintext attack" patented technology

The invention discloses an identity privacy protection system and method oriented to power data security sharing, which combine single-factor combination authentication and identity traceability and utilize the transparency and tamper resistance of a block chain. Comprising an electric power key generation center, an electric power cloud service provider, an electric power data owner, an electric power data user and a block chain, user identity privacy is ensured, safe identity verification is supported, identity traceability is achieved under necessary conditions, and meanwhile safe distribution of keys is achieved. In addition, services and resources are isolated by using groups, so that the flexibility and the expandability of the services and the resources are enhanced. Security analysis and experimental evaluation prove that the method can effectively resist selected plaintext attacks, and meanwhile, high efficiency and practicability are kept.

The invention relates to a ghost imaging neural differential analysis method under a selected plaintext attack condition in the technical field of computational imaging and optical security. The method comprises the following steps: firstly, designing a differentiated plaintext, and deducing a projection speckle by adopting differential calculation; then, constructing a dimensionality reduction simulation training set and an experimental test set based on the structural features of the projection speckles; then, constructing a one-dimensional signal noise reduction neural network model, and training the one-dimensional signal noise reduction neural network model by adopting the dimension reduction simulation training set; and finally, inputting the experimental test set into the trained one-dimensional signal noise reduction neural network model to obtain deciphered speckles, and based on the deciphered speckles, adopting ghost imaging correlation operation to obtain a cracked plaintext image. That is to say, based on the basic principle of ghost imaging encryption, the inherent linear property of the ghost imaging light path is utilized, and the fusion architecture of the differential attack and the neural network is used, so that the cracking of various ghost imaging encryption methods can be realized, and the universality and reliability of ghost imaging encryption analysis can be improved.

The application discloses an image encryption method and system resisting chosen-plaintext attack, and the method comprises the following steps: generating initial values or parameters required by chaotic mapping by taking plaintext image hash value, timestamp and first key together; generating pseudo-random sequence required by image encryption by using pseudo-random number generator based on chaotic system; realizing point scrambling and pixel link diffusion operation of image pixels based on pseudo-random selection mechanism of pseudo-random sequence and multiple DNA encoding and operation; hiding plaintext image hash value and timestamp in extended image based on Chinese remainder theorem and second key, and obtaining final ciphertext image by performing XOR operation on the extended image and noise image generated based on third key. The method enhances the ability of resisting chosen-plaintext attack by making plaintext hash value and timestamp participate in encryption and hiding in ciphertext, and the relationship between plaintext image and ciphertext image depends on plaintext hash value and timestamp, so that the key management of the algorithm is superior to similar encryption algorithms.

The present application relates to the technical field of password security protection, and discloses a puncturable key policy attribute proxy re-encryption method based on lattice cryptography, which comprises an initialization step, an initial key generation step, an encryption step, a puncturable key update step, a decryption step, a re-encryption key generation step and a re-encryption step. The present application allows a receiver to perform a puncturing operation on a specific label locally, thereby autonomously revoking the decryption capability under the corresponding label without the intervention of a data owner or triggering global re-encryption. The receiver-driven revocation mechanism not only realizes fine-grained access control differentiated by labels, but also reduces system overhead while maintaining ciphertext reusability. The present scheme can securely support proxy re-encryption of ciphertext without exposing plaintext or master keys. Based on the security constructed on the LWE assumption, the present method supports multi-bit encryption and can provide effective security protection under quantum attack and chosen plaintext attack models.

The invention belongs to the technical field of optical encryption and information security, and particularly provides an optical asymmetric encryption and decryption method and system based on synchronous compressed wavelet transform, and the method comprises the steps: multiplying a to-be-encrypted image by a first random phase mask, encrypting a first modulation image, and obtaining a preliminary encryption result; multiplying the preliminary encryption result by a second random phase mask, and encrypting the second modulation image to obtain an intermediate encryption result; decomposing the intermediate encryption result into sub-blocks with different frequencies through one-dimensional Haar synchronous compression wavelet transform; the high-frequency coefficient in the horizontal direction is stored as a final encryption result, and encryption of the to-be-encrypted image is completed; and storing the low-frequency coefficient, the high-frequency coefficient in the vertical direction and the high-frequency coefficient in the diagonal direction as a decryption key for decrypting a final encryption result. According to the technical scheme, shear attacks, noise attacks, known plaintext attacks, selected plaintext attacks and special attacks can be effectively resisted.

The invention relates to the technical field of password security protection, and discloses a puncturable key strategy attribute proxy re-encryption method based on a lattice password, which comprises an initialization step, an initial key generation step, an encryption step, a puncture key updating step, a decryption step, a re-encryption key generation step and a re-encryption step. According to the method, the receiver is allowed to perform puncture operation on the specific label locally, so that the decryption capability under the corresponding label is autonomously revoked, a data owner does not need to intervene or trigger global re-encryption, and the revocation mechanism driven by the receiver not only realizes fine-grained access control distinguished according to the label, but also realizes the decryption capability under the corresponding label. And system overhead is reduced while reusability of the ciphertext is maintained. According to the scheme, proxy re-encryption of the ciphertext can be safely supported on the premise that the plaintext or the master key is not exposed. Based on the security of LWE hypothesis construction, the method supports multi-bit encryption, and can provide effective security protection under a quantum attack and selection plaintext attack model.

The invention discloses an RGB-D image encryption and decryption technology based on two-dimensional hyper-chaotic mapping and quaternion discrete cosine transform. The encryption method comprises the following steps: 1) designing a new two-dimensional hyper-chaotic mapping 2D-FLM through composite Fuch mapping and Logistic mapping; 2) carrying out RGB-D image encryption processing based on two-dimensional hyperchaotic mapping 2D-FLM and quaternion discrete cosine transform; and 3) carrying out RGB-D image decryption processing. According to the technology of the invention, through quaternion discrete cosine transform, an RGB image and a depth image are uniformly expressed as a quaternion vector for encryption processing, so that collaborative transformation and unified encryption of heterogeneous multichannel data are realized, and encryption operation is executed by adopting designed 2D-FLM mapping. The pseudo-randomness and the unpredictability are enhanced while the key space (10116) of the system is expanded, and common password attacks can be effectively resisted; according to the encryption strategy, dynamic characteristic parameters related to the plaintext are introduced in the key design, so that the key and the plaintext content are tightly coupled and can dynamically change along with the input image, known plaintext attacks and selected plaintext attacks can be effectively prevented, and the security and reliability of the system are further enhanced.

The application relates to the technical field of image encryption, and discloses a plaintext-related image encryption method based on a bidirectional dynamic window, which comprises the following steps: calculating the hash value of a plaintext image, combining the hash value with a master key to generate a session key, using the session key to disturb a chaotic system to generate first to fourth chaotic sequences; using the first chaotic sequence to perform pixel position replacement on the plaintext image to obtain a scrambled image; performing high-low bit exchange of pixel values on the scrambled image to output an intermediate image; using the second and third chaotic sequences to construct a forward dynamic window scheduling table and a reverse dynamic window scheduling table respectively, and sequentially performing forward window-by-window diffusion calculation and reverse traversal diffusion calculation on the intermediate image; and using a two-dimensional matrix remodeled by the fourth chaotic sequence to perform feedback superposition calculation to output a ciphertext image. The application establishes the correlation between plaintext and encryption parameters, and introduces a bidirectional dynamic window diffusion mechanism, thereby avoiding the regularity of fixed diffusion step length, and improving the ability of the algorithm to resist selective plaintext attacks and the avalanche effect.

The invention discloses a multi-user information sharing method and system based on a probabilistic asymmetric encryption protocol, which introduces a cryptographic security random number and a public quadratic polynomial parameter on the basis of a standard RSA, and generates a ciphertext tuple containing a randomized component through nonlinear mapping, thereby realizing probabilistic encryption, and improving the security of the cryptographic security random number and the public quadratic polynomial parameter. Dictionary attacks and selected plaintext attacks are effectively resisted; in the decryption process, a quadratic congruence equation is constructed, and a plaintext is recovered by using a Tonelli-Shanks algorithm and a Chinese remainder theorem. A forced circulation mechanism of'hop-by-hop decryption-re-encryption 'is adopted to ensure that a data packet of each circulation link has uniqueness and identity binding characteristics, so that accurate tracing of internal data leakage is realized, and meanwhile, the data is ensured not to be tampered through a closed-loop integrity verification mechanism.

This invention belongs to the fields of optical encryption technology and information security technology, specifically providing an optical asymmetric encryption and decryption method and system based on synchronous compressed wavelet transform. The method includes: multiplying the image to be encrypted with a first random phase mask to encrypt a first modulated image, obtaining a preliminary encryption result; multiplying the preliminary encryption result with a second random phase mask to encrypt a second modulated image, obtaining an intermediate encryption result; decomposing the intermediate encryption result into sub-blocks of different frequencies using a one-dimensional Haar synchronous compressed wavelet transform; saving the high-frequency coefficients in the horizontal direction as the final encryption result to complete the encryption of the image to be encrypted; and saving the low-frequency coefficients, the high-frequency coefficients in the vertical direction, and the high-frequency coefficients in the diagonal direction as decryption keys for decrypting the final encryption result. This invention effectively resists shearing attacks, noise attacks, known-plaintext attacks, chosen-plaintext attacks, and special attacks.

Disclosed in the present invention are a method and a system for constructing an AKE protocol from a PKE algorithm having errors. The method comprises: 1) converting a one-way under chosen-plaintext attack (OW-CPA) PKE having a decryption error into an indistinguishability under chosen plaintext attack KEM that can leak an error, and recording same as an IND-CPAwF KEM, which comprises a key generation algorithm of the KEM, an encapsulation algorithm of the KEM, and a de-encapsulation algorithm of the KEM; in the encapsulation algorithm of the KEM, an encapsulation message m is inputted into a hash function H(.), so as to export an encapsulation key K=H(m); in the de-encapsulation algorithm of the KEM, an encapsulation message m' obtained by decryption is inputted into a hash function H(.), so as to export an encapsulation key K'=H(m'); 2) converting an AKE protocol which cannot use a KEM having errors into an AKE protocol which can use a KEM having errors. The present invention provides greater parameter selection flexibility for a PKE algorithm designer.

The application discloses a kind of group key agreement methods of synchronization in digital twin network, based on elliptic curve cryptography, self-authentication key, sibling intractable function family, it is proposed that group key agreement scheme of synchronization in digital twin network, first, control center completes the initialization of system, generates system parameter, and deploys digital twin generation key;Then multiple digital twins carry out synchronous group key agreement and group key generation, finally, multiple digital twins utilize group key and carry out safe data transmission.In addition, digital twin can choose to dynamically leave or join group key agreement.The application guarantees the synchronism, confidentiality, authentication of multiple digital twin communication, satisfies the indistinguishability of chosen plaintext attack under the random oracle model, achieves higher security while having higher efficiency.

The application discloses a medical image selection encryption method based on a DICOM information generated key, relates to the technical field of image encryption, and solves the problems of low encryption efficiency of the existing medical image encryption technology, security defects such as incapability of resisting known plaintext and selected plaintext attacks, etc.The encryption method uses patient information in a DICOM file to generate an encryption key in a key generation stage, makes plaintext highly related to ciphertext, greatly improves the security of the ciphertext, and uses the key generated by the generation model to encrypt a region of interest of a medical image; in the encryption stage, index scrambling and two-dimensional bidirectional diffusion are adopted, the security of the image is ensured, and the encryption efficiency of the medical image is improved.The data information in the medical file DICOM is used for the generation of a key stream, and the plaintext correlation is greatly improved.

The invention discloses a fractional order multi-scroll hyper-chaos and self-adaptive region image encryption method and a fractional order multi-scroll hyper-chaos and self-adaptive region image encryption system. The method comprises the following steps: acquiring a to-be-encrypted original image; based on a preset fractional order multi-scroll hyperchaotic system, constructing an image encryption model, and generating a multi-dimensional chaotic sequence; using the multi-dimensional chaotic sequence to drive a self-adaptive region transformation algorithm to carry out global scrambling of pixel positions on the original image; on the basis of scrambling, double-layer diffusion encryption of an original image is completed by combining pixel internal bit exchange and inter-pixel diffusion based on a binary tree structure, and a ciphertext image is generated. According to the method, known plaintext attacks and selected plaintext attacks can be effectively resisted, the security of the chaotic system in data encryption is improved, the key space is remarkably increased, the exhaustive attack resistance of the system is enhanced, the robustness is good, and even under the condition that part of data is lost or is interfered by noise, the security of the system is improved. And image restoration with relatively high fidelity can still be realized.