Beijing University of Chemical Tehcnology

Ningbo University

Wenzhou University

Juhua Group Co., Ltd

Zhejiang Quzhou Jusu Chemical Industry Co.,ltd

Yunfei Yu

Pengjun Wang

Yuejun Zhang

Jianfeng Chen

Gang Li

Huihong Zhang

Guangwen Chu

Bo Chen

Liangliang Zhang

Haizhen Yu

Zhigang Wu

Liyang Zhou

Jiana Lian

Jinyuan Lin

Yidong Zhang

Jihong Tong

The present application provides a continuous preparation system and method for vinylidene chloride. In the present application, by coupling two stages of high gravity reactors, the product vinylidene chloride and water vapor are distilled from a reaction system in form of an azeotrope by adopting a water vapor steam stripping method, and the product obtained using the method has high purity. In addition, by combining steam stripping and high gravity, trichloroethane and alkali solution are rapidly mixed for mass transfer, and the product vinylidene chloride is rapidly distilled from the reaction system in form of the azeotrope (based on rapid diffusion of water vapor), such that the reaction proceeds continuously towards the direction of producing vinylidene chloride, thus significantly improving the conversion rate. As proved by a test apparatus, the present application can stabilize the purity of the vinylidene chloride product at 98% or more (mass fraction), decrease the TOC value of chloride salt wastewater to 100 mg/L or less, and decrease the consumption of materials and the cost of subsequent salt-containing wastewater treatment.

Continuous preparation system and method for vinylidene chloride

A control flow attacks based on return address signatures comprises: using a return address as a push return address when a response is given to an interrupt service routine; generating an encrypted push return address by an XOR encryption circuit by means of an n-bit binary key generated by a pseudo random number generator; then, generating a push_address signature value by an MD algorithm signature circuit; when the response to the interrupt service routine is over, reading an n-bit binary address out of a stack to serve as a pop return address; generating an encrypted pop return address by the XOR encryption circuit; generating a pop address signature value by the MD algorithm signature circuit; comparing the push_address signature value with the pop address signature value; and determining whether or not a data processor is under a control flow attack according to a comparison result.

Detection method of control flow attacks based on return address signatures

The disclosure discloses a method for defending control flow attacks. When a data processor gives a response to an interrupt routine, a return address and a binary key are input to an encryption circuit to be encrypted to obtain an encrypted return address, and the obtained encrypted return address is synchronously written into a stack of the data processor and an built-in register bank; when the response given to the interrupt routine by the data processor is finished, the encrypted return address is read from the tack of the data processor and the built-in register bank; afterwards, the two encrypted return addresses are decrypted by first and second decryption circuits respectively to obtain two decrypted return addresses; and the two decrypted return addresses are compared to draw a conclusion whether the data process suffers from a control flow attack, and data processor determines to continue or terminate the routine accordingly.

Method for defending control flow attacks based on XOR gates

Growing community of inventors

Zhejiang, China

Yunfei Yu