Method and device for securely configuring a terminal by means of a startup data storage device

A device for configuring a terminal, the device being external to said terminal, able to communicate with said terminal and comprising data storage means, said storage means comprising:

• a first memory area with secure write-mode access, comprising a boot program for an operating system of said terminal,
• a second memory area comprising a first digitally-signed file, said first file comprising a kernel of an operating system of said terminal,
• a third memory area comprising at least one second digitally-encrypted file,
• an initialization of said terminal triggering,
• a step of executing said boot program,
• a step of starting up said kernel, said startup step being intended to be triggered only if a digital signature of said first file is valid,
• a step of constructing, in RAM memory of said terminal, a first logical file structure from said second file, so as to enable a user to access data contained in said second file.