System, device, and method of selectively allowing a host processor to access host-executable code

A host apparatus comprising:

• a host processor;
• a memory module comprising a memory to maintain a host-executable code to be executed by said host processor;
• and
• a security module comprising logic to authenticate said host-executable code and to selectively allow said host processor to access said host-executable code based on an authenticity of said host-executable code,
• wherein:
• said host-executable code is adapted to contain update code that, when executed by said host processor, causes said host processor to change said host-executable code on said memory module, said update code is different from said host-executable code;
• said security module to verify the authenticity of said host-executable code;
• said security module to verify the authenticity of said update code;
• said security module is adapted to send data to said host processor during the process of said verification, that causes said host processor to wait until said verification processes complete;
• and
• if host-executable code was determined by said verification process to be non-authentic and said update code was determined by said verification process to be authentic, then said security module sends data to said host processor, wherein said data causes said host processor to execute said update code.

A method of selectively allowing a host processor to access a host-executable code, said method comprising:

• storing host-executable code on a memory module;
• allowing a security module to selectively allow a host processor to access said host-executable code, comprising:
• dividing said host-executable code into at least two parts;
• allowing said security module to verify the authenticity of said host-executable code;
• allowing said security module to restrict access of said host processor to said first part of host-executable code to read-only access while authenticity of said first part of host-executable code is being verified by said security module;
• allowing said host processor to execute at least a portion of the code of said first part during a time period that is at least partially overlapping the time period at which said security module carries out said verification;
• and
• allowing said first part of host-executable code to contain one or more instructions that, when executed by said host processor, cause said host processor to not execute code of other parts but the said first part before said security module signals that all said host-executable code is authentic.

A method of selectively allowing a host processor to access a host-executable code, said method comprising:

• storing host-executable code on a memory module;
• storing update code that, when executed by said host processor, causes said host processor to change said host-executable code on said memory module said update code is different from said host-executable code;
• allowing said security module to selectively allow said host processor to access said host-executable code, comprising:
• allowing said security module to verify the authenticity of said host-executable code;
• allowing said security module to verify the authenticity of said update code;
• allowing said security module to send data to said host processor, during said verification process wherein said data causing said host processor to wait until said verification process completes;
• and
• allowing said security module to carry out a decision process once verification process completes,
• wherein:
• if said host-executable code was found by said verification process to be non-authentic and said update code was found by said verification process to be authentic, then said decision process results in allowing said security module to send data to said host processor wherein said data causes said host processor to execute said update code;
• and
• if said host-executable code was found by said verification process to be authentic, then said decision process results in allowing said host processor to execute said host-executable code.