4results about How to "Increase overhead" patented technology

The invention discloses a VSAT-TDMA time delay tracking method based on decoding verification, and belongs to the technical field of satellite communication. According to the method, demodulation and signaling analysis are carried out on a main station receiving signal, a small station frame plan is generated, and a signaling initial time delay estimation value is obtained by comparing burst theoretical occurrence time with actual receiving time; receiving a small station burst signal and completing decoding verification, and reserving a preorder burst signal conforming to a set rule; differential correlation operation is carried out on the effective signal to obtain a correlation peak position, a time delay change trend is obtained through smooth fitting, a subsequent burst initial position is predicted based on the trend, a receiving window is dynamically adjusted, and time delay tracking is completed. Effective samples are screened through decoding verification, time delay extraction accuracy is improved, detection jitter is filtered out, channel time-varying characteristics are adapted, uplink access synchronization stability of the system is guaranteed, the method can be deployed in an existing satellite communication system, and communication reliability is improved.

This application discloses a method, apparatus, and medium for implementing secure socket communication within the operating system kernel, belonging to the field of computer systems and network communication technology. This method registers a new secure socket type at the socket layer of the operating system kernel and associates it with a customized set of operation functions. Applications only need to create sockets of this type and inject cryptographic parameters through standard system calls to establish a connection, thereby obtaining transparent, end-to-end automatic encrypted communication capabilities. During transmission, data is encrypted in kernel mode by calling the native crypto subsystem API through a rewritten send function and an authentication tag is attached. During reception, the rewritten receive function automatically performs decryption and integrity verification. This scheme avoids reliance on large external security libraries, improves security and performance, and decentralizes encryption / decryption, resource management, and other processes to the kernel mode, providing upper-layer applications with easy-to-use, lightweight, high-performance, and highly secure kernel-level transparent secure communication.

This invention discloses a method and device for constructing a cross-island heterogeneous federated learning system based on homomorphic encryption. After local training on the client, the local model is packaged and sparsified at the packet granularity. The sparsed packet data is homomorphically encrypted, and the ciphertext and mask are sent to a parameter server. The parameter server aggregates the data according to the client's ciphertext weights and sends the aggregated ciphertext global model and mask to the client. The client decrypts the global ciphertext and unpacks it to obtain the global model, and updates its local model. The client calculates and returns a sketch of its local model. By clustering the sketch, the fastest client in each cluster is selected as a participant in the next round of training, and the contribution is calculated based on the sketch to obtain the aggregation weights for the next round. The trained local model is then applied to the cross-island heterogeneous federated learning system. This invention can improve the efficiency of homomorphic encryption while protecting privacy, and simultaneously resist the negative impact of lagging on model synchronization.

The application discloses a virtual RDMA device based on DPDK and a use method thereof. The virtual RDMA device based on DPDK comprises a front-end virtio-rdma device, which is used for receiving an RDMA device operation request initiated by an application program in a virtual machine, encapsulating the request as an instruction conforming to a virtio protocol, and sending the instruction to a back-end vhost-user- rdma device through a vring; and the back-end vhost-user- rdma device is used for simulating the function of a real RDMA network card, the device can acquire and analyze the instruction conforming to the virtio protocol from a circular queue vring, execute corresponding RDMA device operations, and return the operation results to the front-end virtio-rdma device through the vring. The application can get rid of the dependence on the real RDMA device, and can improve the resource utilization, system flexibility and safety.