多层壳 meaning in English

multilayered shell

Sparkey usb dongle based on usb port , it is very small and elegant , plug and play , offers multiple envelopes protection with strong anti - dump function , offers api , user define algorithm , file protection , encode and decode function etc
加密锁基于usb接口，体积小巧，即插即用，加密强度高，提供高强度多层壳外壳加密，各类型文件加密，提供api函数调用接口和加码解码等功能。