Patent ID: 9215073
Filing Date: 2015-12-15
Classification: H04L

Abstract:
1. A key insulation method, comprising: generating, by a user equipment, an initial user private key according to a randomly selected parameter s, a preset first cryptographic hash function H acquiring, by the user equipment, a helper updated key for a time segment i from the helper device, and updating by the user equipment a user private key for a time segment j according to the helper updated key for the time segment i to obtain a user private key for the time segment i, wherein i and j are integers, i>j≧0, an initial time segment is a time segment 0, the initial user private key is a user private key for the time segment 0, and the helper updated key for the time segment i is obtained by updating a helper updated key for a time segment i−1 according to the first cryptographic hash function H wherein the helper device is a device of higher security than the user equipment, the helper initial key is UK wherein the generating by the user equipment the initial user private key according to the parameter s, the preset first cryptographic hash function H generating by the user equipment the initial user private key TSK wherein the updating by the user equipment the user private key for the time segment j according to the helper updated key for the time segment i to obtain the user private key for the time segment i includes: obtaining by the user equipment the user private key TSK