Patent ID: 9647845
Date: 2017-05-09
CPC Classifications: H04L

Claim:
1. A key downloading method, comprising: sending a device sequence number DSN and a device identity authentication request to a remote key system (RKS) server via a device terminal; receiving a working certificate public key RKS_WCRT_PK and a cipher text AT_TK1 sent by the RKS server, via the device terminal, wherein the AT_TK1 cipher text is obtained by encrypting an authentication token AT and a first transmission key component TK1 by using a device identity authentication pubic key DIK_PK; verifying if a digital signature of RKS_WCRT_PK is valid by using a root public key certificate RKS_RCRT, and if valid, decrypting the AT_TK1 cipher text by using a device identity authentication private key DIK_SK to obtain clear texts AT and TK1, via the device terminal, wherein DIK_PK and DIK_SK form a non-symmetric key pair; generating a third random number as a second transmission key component TK2, performing XOR on TK1 and TK2 to obtain a transmission key TK, calculating SHA256 verification value of TK to obtain TK_SHA2, via the device terminal; encrypting AT, TK2, and TK_SHA2 by using RKS_WCRT_PK to obtain a cipher text AT_TK2_TK_SHA2 and sending the cipher text AT_TK2_TK_SHA2 to the RKS server, via the device terminal; receiving a key cipher text sent by the RKS server via the device terminal, wherein the key cipher text is obtained through encrypting the key to be downloaded by TK; decrypting the key cipher text by using TK to obtain a key clear text, storing the key in a security module, via the device terminal; and judging if the key downloading is complete, and if complete, clearing AT, TK, and RKS_WCRT_PK, via the device terminal.