31 results about "Chosen-ciphertext attack" patented technology

The public-key encryption method uses the sender-side apparatus by the creator of a ciphertest and creates the ciphertext of a plaintext x (∈ {0, 1}n), in y1=f (x0k1G(r)), y2=H (x0k1G(r))r with respect to the published trapdoor-equipped unidirectional function f and the random functions G, H. Meanwhile, the receiver of the ciphertext, who has received the ciphertext by the receiver-side apparatus via the communications line, performs the decryption processing with the use of f−1, i.e., the secret key, in accordance with the steps inverse to those of the encryption processing.

The public-key encryption method uses the sender-side apparatus by the creator of a ciphertest and creates the ciphertext of a plaintext x (ε{0, 1}n), in y1=f(x0k1G(r)), y2=H(x0k1G(r))r with respect to the published trapdoor-equipped unidirectional function f and the random functions G, H. Meanwhile, the receiver of the ciphertext, who has received the ciphertext by the receiver-side apparatus via the communications line, performs the decryption processing with the use of f−1, i.e., the secret key, in accordance with the steps inverse to those of the encryption processing.

The invention relates to a plaintext-related image encryption method based on PUD adaptive decomposition, which performs adaptive PUD decomposition on plaintext images, and performs scrambling-diffusion operations on decomposed two-dimensional components. The encryption key used in this method is related to the plaintext, and the obtained encrypted image can efficiently resist chosen plaintext attack and chosen ciphertext attack, and has strong robustness against filtering noise attack, clipping attack and differential attack, further improving The security and robustness of encrypted images can be applied in the fields of image security and image confidential communication.

The invention belongs to the technical field of information security and particularly relates to a color image encryption method based on a hybrid domain and an LSS type coupled map lattice. The method comprises the steps of inputting a color plaintext image, separating red, green and blue three primary color components of the plaintext image to obtain corresponding three matrixes, generating a parameter and an initial value of the LSS type coupled map lattice through combination of a key, and generating key streams through utilization of the LSS type coupled map lattice; carrying out two-dimensional discrete wavelet transform on the three matrixes to obtain three groups of sub-bands; keeping a high and low frequency sub-band unchanged, scrambling the other sub-bands through utilization ofthe key streams, and shrinking the scrambled sub-bands; switching the content of the shrunk sub-bands; carrying out the two-dimensional discrete wavelet transform on the three groups of sub-bands toobtain three encryption components; and blocking the three encryption components, and carrying out bit level diffusion operation on the blocked matrixes through utilization of the key streams to obtain a ciphertext image. According to the method, statistics attacks, known and chosen plaintext attacks and chosen ciphertext attacks can be effectively resisted.

Provided is a verifiable public key encryption method. The encryption method includes steps: initialization, encryption, and decryption. In terms of security, the method has a mathematics hypothesis with dual difficulties referring to factorization and Diffie-Hellman problem. In other words, an attacker has to simultaneously solve the mathematical problem of the two calculations if he wants to crack the encryption method. The encryption method is designed by partly employing the concept of the trapdoor one-way function, the method has semantic security and can resist chosen plaintext attack and chosen ciphertext attack, and good practical values are provided.

The invention discloses a method for encrypting a public key in a signed quadratic residue class group. The method comprises the steps of 1, setting system parameters; 2, generating a secret key; 3, selecting a random number by a sender, carrying out encryption on a message, and generating a ciphertext data packet; 4, sending the ciphertext data packet to a receiver by the sender through a public channel; and 5, verifying the effectiveness of the ciphertext after the receiver receives the ciphertext data packet, decrypting the ciphertext data packet by using a private key, and acquiring the message. The method disclosed by the invention satisfies the confidentiality, the integrity and the chosen-ciphertext attack security simultaneously, and realizes public verification of the ciphertext legitimacy; the method does not use bilinear pairings and one-time signatures which are time-consuming, so that defects of other public key encryption methods in which the ciphertext legitimacy is verified by using the bilinear pairings and the one-time signatures are overcome, thereby having higher computational efficiency and higher practical values.

The invention belongs to the technical field of information security, and in particular relates to a color image encryption method based on compressed sensing and deformable coupling image lattice, comprising: separating three primary color components of a color plaintext image to obtain a component matrix; combining with an initial key, through SHA-256 The function updates the parameters and initial values ​​of the deformation coupling image lattice, obtains the measurement matrix and key stream by iterating the space-time chaotic system; divides the component matrix and obtains a new image matrix; generates a sparse dictionary for the new image matrix; uses the measurement matrix to measure the new image to obtain the intermediate image; transform the intermediate image into a coefficient matrix, perform scrambling and diffusion operations in the frequency domain to obtain a scrambled diffusion matrix; use the key stream matrix, perform pixel-level diffusion operations on the scrambled diffusion matrix, and obtain the final encryption text images. The invention effectively resists statistics, known and selected plaintext, selected ciphertext attacks, etc., improves security and encryption effect, and has good application prospect.

Embodiments of the invention provide an encryption method, a decryption method and electronic equipment. The method comprises steps of acquiring a public key, a plaintext and a first bit string of a preset length through first electronic equipment, wherein the public key comprises the only defect trapdoor function; acquiring a key pair of a one-time signature scheme by the first electronic equipment, wherein the public pair comprises a verification secret key and a signature secret key corresponding to the verification secret key; acquiring a middle cryptograph set according to the only defect trapdoor function, the first bit string of the preset length, the plaintext and the verification secret key; signing the middle cryptograph set by the first electronic equipment according to the signature secret key, and acquiring a signature of the middle cryptograph set; and forming a final cryptograph by combing the verification secret key, the middle cryptograph set and the signature of the middle cryptograph set, and outputting the final cryptograph. Therefore, anti-selection cryptograph attack is achieved.