Abstract: The rigid protective case convenient for mounting and removal is provided, including a case body, a locking portion, and a resetting portion; the case body includes a main case and an auxiliary case; the auxiliary case may move away from or approach the main case, and an accommodating space configured to place an electronic device is enclosed and formed between the main case and the auxiliary case; the locking portion is mounted on the main case and can lock or unlock the auxiliary case that approaches the main case; the resetting portion includes a first magnetic body mounted on the main case and a second magnetic body mounted on the auxiliary case; and the first magnetic body and the second magnetic body are mutually exclusive to drive the auxiliary case to move away from the main case.

Abstract: A method for remotely acquiring secret key, comprising steps of detecting an injection key acquisition instruction; generating a temporary key pair when the injection key acquisition instruction is detected; acquiring a locally stored private key in a random key pair, and using a private key in the random key pair to perform signature on a public key in the temporary key pair to generate a temporary key signature; acquiring a first identity authentication certificate; sending the temporary key signature and the first identity authentication certificate to a remote injection server; receiving an injection key ciphertext signature and a second identity authentication certificate which is returned by the remote injection server according to the temporary key signature and the first identity authentication certificate; and acquiring and storing an injection key according to the injection key ciphertext signature and the second identity authentication certificate.

Abstract: A method for remotely acquiring secret key, comprising steps of detecting an injection key acquisition instruction; generating a temporary key pair when the injection key acquisition instruction is detected; acquiring a locally stored private key in a random key pair, and using a private key in the random key pair to perform signature on a public key in the temporary key pair to generate a temporary key signature; acquiring a first identity authentication certificate; sending the temporary key signature and the first identity authentication certificate to a remote injection server; receiving an injection key ciphertext signature and a second identity authentication certificate which is returned by the remote injection server according to the temporary key signature and the first identity authentication certificate; and acquiring and storing an injection key according to the injection key ciphertext signature and the second identity authentication certificate.