Patent ID: 7392384
Filing Date: 2008-06-24
Classification: H04L

Abstract:
1. A method for validating a received secure key block, comprising: receiving a control field, encrypted key field, and message authentication code (MAC) field appended to the control field and encrypted key field, the encrypted key field generated by applying an encryption algorithm to the clear key and appending a control field to the encrypted key field, wherein the control field contains attributes of the clear key, the MAC field cryptographically tying the control field to the encrypted key field; applying a MAC algorithm using a first key across a control field and an encrypted key field to create a computed MAC field, wherein the control field and the encrypted key field are contained within the received secure key block; comparing a received MAC field to the computed MAC field, wherein the received MAC field is contained within the received secure key block; and decrypting the encrypted key field to reveal at least one clear key using a second key if the received MAC field is equal to the computed MAC field, wherein tampering with the secure key block renders the received MAC field unequal to the computed MAC field.