7 results about "Elliptic curve cryptosystem" patented technology

The invention discloses a medical shared data protection method and system using an elliptic curve cryptosystem. The process of the invention is as follows: an image owner, a data embedder and a receiver firstly pass identity verification of a trusted authentication center to obtain an exclusive elliptic curve public and private key pair; an image owner generates a first shared key by using a private key of the image owner and a public key of a receiver, separates a DICOM file into image data and metadata, and encrypts the image data after lossless compression. And the data embedder generates a second shared key by using the private key of the data embedder and the public key of the receiver, encrypts the electronic medical record information, embeds the electronic medical record information into the encrypted DICOM image, and then sends the electronic medical record information to the receiver. And the receiver reconstructs the shared key by using the private key of the receiver and the public keys of the data embedder and the image owner, extracts the electronic medical record information and reconstructs the image. The method effectively guarantees the safety of DICOM medical images and electronic medical records, and is suitable for cross-mechanism remote medical cooperation.

The invention provides a metro vehicle network data secure communication method, which comprises the following steps of: firstly, acquiring metro vehicle network communication data, and obtaining metro vehicle network communication characteristic data; then, plaintext data is formed, and a secret key is generated to construct a symmetric encryption function; signing the plaintext data to generate signature blocks, and performing block encryption processing on the plaintext data to form ciphertext data; then encrypting the key based on an elliptic curve cryptosystem to generate an encryption key block, and forming metro vehicle network transmission data; and finally, based on an elliptic curve cryptosystem, carrying out legality verification on the metro vehicle network transmission data, and decrypting the key so as to decrypt the ciphertext data, thereby obtaining metro vehicle network communication data. According to the secure communication method, replay attack, man-in-the-middle attack and side channel attack can be effectively resisted, and confidentiality and integrity of vehicle control instructions and passenger information are ensured.

The invention discloses a rapid implementation method for scalar multiplication in an elliptic curve cryptosystem. According to the method, the scalar of the SM2 algorithm is expanded into 256-bit binary data for representation, then multiple pieces of point data are pre-stored, the point data are divided into two parts, when scalar multiplication operation is carried out, corresponding point data are matched from the first pre-stored part and the second pre-stored part, and then point addition calculation is carried out according to the matched point data. According to the method, point addition and point doubling times in fixed base scalar multiplication are reduced, so that scalar multiplication efficiency is improved, signature performance is improved, private key blinding and virtual point operation technologies are used, test channel attacks are resisted, hardware can adopt partial parallel scheduling, and performance is further improved; for a PCIE board card chip with a relatively large internal storage space, fixed base scalar multiplication can be popularized to random point scalar multiplication in a mode of pre-storing a signature verification public key, so that the signature verification performance is prompted.

A method of communicating a secret between a sender and a recipient is disclosed. The method comprises sending information identifying secrets selectable by the recipient and receiving a first public key of an elliptic curve cryptography system, corresponding to a first secret selected for access by the recipient and for which a first private key is accessible to the recipient. A second public key is received, corresponding to a second secret not selected for access by the recipient, wherein a corresponding second private key is not available to the recipient. First and second secrets encrypted by means of the respective first and second public keys are sent to the recipient, wherein the first secret is accessible to the recipient by means of the first private key, the second secret is inaccessible to the recipient, and the sender is unable to distinguish between the first and second secrets.

A method of communicating a secret between a sender and a recipient is disclosed. The method comprises sending information identifying secrets selectable by the recipient and receiving a first public key of an elliptic curve cryptography system, corresponding to a first secret selected for access by the recipient and for which a first private key is accessible to the recipient. A second public key is received, corresponding to a second secret not selected for access by the recipient, wherein a corresponding second private key is not available to the recipient. First and second secrets encrypted by means of the respective first and second public keys are sent to the recipient, wherein the first secret is accessible to the recipient by means of the first private key, the second secret is inaccessible to the recipient, and the sender is unable to distinguish between the first and second secrets.

The present application relates to a kind of separate point multiplication method and hardware circuit, belong to cryptography field.The method of the present application includes: three parts;Wherein, the first part is NAF encoding operation, the continuous point multiplication calculation process of second part is point expansion calculation, the continuous point addition / subtraction calculation process of third part is point accumulation calculation.The method of the present application includes: fixed point preprocessing mode, random point point multiplication serial mode, random point point multiplication parallel mode, random point point multiplication pipelined mode, fixed point acceleration point multiplication mode, random point fixed point mixed pipelined mode.The present application combines the application characteristics of ECC elliptic curve cryptosystem, provides six application modes, with more extensive and more flexible application effect, can obtain better performance under the constraint of different hardware resources.

The invention relates to the technical field of key management, and discloses an Ad hoc network group key management method, which comprises the following steps of: constructing a logic key tree based on an elliptic curve cryptosystem; mapping the elliptic curve points into integer field numerical values through a mapping function, wherein the integer field numerical values are used for generating each node key of the logic key tree; when a group is initialized, dynamically generating a group key through a multi-party key negotiation protocol; when a new member joins, adjusting a logic key tree structure and updating a related node key to ensure that the new member cannot decrypt the communication content before joining; and when the member exits, updating the node key on the related path of the exit member to ensure that the exit member cannot decrypt the communication content after the exit. According to the method, a logic key tree structure and multi-party key negotiation are adopted, and the method has the key independence characteristic. The method is based on a logic key tree structure, supports node dynamic event group key updating, meets the requirements of group key forward and backward security, and is suitable for an Ad hoc network environment.