Key transformation unit for a tamper resistant module

• US 7,707,408 B2
• Filed: 10/25/2007
• Issued: 04/27/2010
• Est. Priority Date: 02/21/1997
• Status: Expired due to Fees

• Current Assignee: Multos Ltd
• Original Assignee: Multos Ltd
• Inventors: Everett, David Barrington, Richards, Timothy Philip, Miller, Stuart James, Viner, John Charles, Simmons, Ian Stephen, Peacham, Anthony David
• Primary Examiner(s): SMITHERS, MATTHEW
• Application Number:
  US11/977,919
• Publication Number:
  US 20080091956A1
• Time in Patent Office: 915 Days
• Field of Search: 713/172
• US Class Current: 713/160
• CPC Class Codes: G06F 21/51 at application loading time, e.g. accepting, rejecting, starting or inhibiting executable software based on integrity or source reliability
• CPC Class Codes: G06F 21/57 Certifying or maintaining trusted computer platforms, e.g. secure boots or power-downs, version controls, system software checks, secure updates or assessing vulnerabilities
• CPC Class Codes: G06F 21/77 in smart cards
• CPC Class Codes: G06F 2221/2115 Third party
• CPC Class Codes: G06K 19/0719 at least one of the integrated circuit chips comprising an arrangement for application selection, e.g. an acceleration sensor or a set of radio buttons application selection on smart cards using pure software control, see G07F7/10
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/355 Personalisation of cards for use
• CPC Class Codes: G06Q 20/3552 Downloading or loading of personalisation data
• CPC Class Codes: G06Q 20/3574 Multiple applications on card
• CPC Class Codes: G06Q 20/35765 Access rights to memory zones
• CPC Class Codes: G06Q 20/4097 using mutual authentication between devices and transaction partners
• CPC Class Codes: G06Q 20/40975 using encryption therefor
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: G07F 7/1016 Devices or methods for securing the PIN and other transaction-data, e.g. by encryption arrangements for secret communication, see H04L9/00
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823

Abstract

Methods, apparati, and computer-readable media for securely transporting a software application onto a tamper resistant module (TRM) (103) by using an individualized TRM key set. A method embodiment of the present invention comprises: storing a key pair unique to the TRM (103) in a memory located on the TRM (103), where the key pair comprises a TRM public key (150) and a TRM private key (190); retrieving the TRM public key from the TRM; encrypting a portion of the software application using the TRM public key (150); transmitting the encrypted software application to the TRM (103); and recovering and decrypting the encrypted software application using the TRM private key (190).

Claims

1. A method for securely loading an executable software application from an application provider onto a tamper resistant module (TRM) having a memory over a communications network, said method comprising the steps of:

providing a TRM private key and a TRM public key for said TRM;

encrypting at least one portion of said executable software application using an associated transport key, each said portion also having an associated location;

creating an application unit which comprises said portion of said executable software application;

encrypting said associated transport key and an indicator of said associated location using said TRM public key;

forming a key transformation unit (KTU), said KTU comprising said associated transport key and said indicator;

transmitting said application unit and said KTU to said TRM;

decrypting said KTU using said TRM private key to recover said associated transport key and said indicator;

identifying said portion of said executable software application;

decrypting said portion of said executable software application using said associated transport key;

storing said portion of said executable software application in said memory on said TRM for subsequent execution;

providing for a software application provider (SAP) an SAP key set comprising an SAP public key and an SAP private key, wherein said step of encrypting at least one portion of said executable software further comprises using said SAP private key to sign said portion, thereby producing a signed application;

providing for a certification authority (CA) a CA key set comprising a CA public key and a CA private key;

encrypting said SAP public key using said CA private key to produce an application load certificate; and

transmitting said signed application and said application load certificate to said TRM.

2. The method of claim 1, further comprising the step of verifying said application load certificate at the TRM with said CA public key.

3. The method of claim 1, further comprising the step of verifying said signed application using the SAP public key from said application load certificate to produce a verified application unit.

4. The method of claim 3, further comprising the step of comparing the verified application unit to the application unit to determine whether said verified application unit and said application unit are equivalent.

5. Tamper resistant module (TRM) apparatus, comprising:

at least one TRM having a memory;

an executable software application provided by a software application provider to said TRM;

a communications link coupled to said TRM and to said software application provider;

a TRM public key and a TRM private key for said TRM; and

an arrangement;

wherein;

a portion of said executable software application is encrypted by said software application provider using an associated transport key, each said portion having an associated location;

an application unit is created, said application unit comprising said portion of said executable software application;

said associated transport key and an indicator of said associated location are encrypted using said TRM public key;

a key transformation unit (KTU) is formed, said KTU comprising said associated transport key and said indicator;

said application unit and said KTU are transmitted to said TRM over said communications link;

said KTU is decrypted on said TRM using said TRM private key to recover said associated transport key and said indicator;

said portion of said executable software application is identified;

said portion of said executable software application is decrypted on said TRM using said associated transport key for each said portion to recover said executable software application;

said executable software application is stored on said TRM for subsequent execution;

a certification authority (CA) is provided with a CA key set comprising a CA public key and a CA private key;

a software application provider (SAP) is provided with an SAP key set comprising an SAP public key and an SAP private key;

said CA private key is used to sign said SAP public key to produce an application load certificate;

said SAP private key is used to further sign said portion of said executable software application to produce a signed application; and

said signed application and said application load certificate are transmitted to said TRM.

6. The apparatus of claim 5, wherein the TRM verifies said application load certificate with said CA public key.

7. The apparatus of claim 6, wherein said TRM verifies the signed application using the SAP public key from said application load certificate to produce a verified application unit.

8. The apparatus of claim 7, wherein said verified application unit is compared to said application unit to determine whether said verified application unit and said application unit are equivalent.