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Systems and methods using cryptography to protect secure computing environments

DC
  • US 7,590,853 B1
  • Filed: 08/20/2007
  • Issued: 09/15/2009
  • Est. Priority Date: 08/12/1996
  • Status: Expired due to Fees
First Claim
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1. A method performed by an electronic appliance comprising at least one protected processing environment, the method comprising the steps of:

  • receiving a first load module and an associated first digital signature;

    receiving a second load module and an associated second digital signature;

    authenticating the first digital signature using a first cryptographic key;

    authenticating the second digital signature using a second cryptographic key;

    conditionally executing the first load module in a first processing environment of the electronic appliance based at least in part on a result of the step of authenticating the first digital signature, wherein the first processing environment has a first assurance level; and

    conditionally executing the second load module in a second processing environment of the electronic appliance based at least in part on a result of the step of authenticating the second digital signature, wherein the second processing environment has a second assurance level that is different from the first assurance level;

    wherein the protected processing environment is operable to impede tampering by a user of the electronic appliance with at least the step of authenticating the first digital signature and the step of authenticating the second digital signature.

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