US6026293A — System for preventing electronic memory tampering

Claim 1

Independent Claim 59 words

A cellular telephone comprising: a microprocessor; and a memory; wherein the microprocessor performs a hash calculation on contents of the memory to derive an audit hash value, which audit hash value is compared to a valid hash value previously derived from perlormance of the hash calculation on authentic memory contents, said hash calculation and comparison being secure from tampering.

Claim 2

Dependent Claim 59 words

A cellular telephone comprising: a microprocessor; and a memory; wherein the microprocessor performs a hash calculation on contents of the memory to derive an audit hash value, which audit hash value is compared to a valid hash value previously derived from perlormance of the hash calculation on authentic memory contents, said hash calculation and comparison being secure from tampering.

Claim 3

Dependent Claim 22 words

The cellular telephone claimed in claim 1, wherein the audit hash value is periodically derived and compared to the valid hash value.

Claim 4

Dependent Claim 24 words

The cellular telephone claimed in claim 2, wherein the periodic derivation of the hash value is performed pursuant to expiration of a hardware-based timer.

Claim 5

Dependent Claim 17 words

The cellular telephone claimed in claim 1, wherein said memory includes a flash memory and an EEPROM.

Claim 6

Dependent Claim 24 words

The cellular telephone claimed in claim 4, wherein the audit hash value derived based on selected contents of the flash memory and the EEPROM.

Claim 7

Dependent Claim 16 words

The cellular telephone claimed in claim 5, wherein the selected contents include an electronic serial number.

Claim 8

Dependent Claim 15 words

The cellular telephone claimed in claim 5, wherein the selected contents include microprocessor program code.

Claim 9

Dependent Claim 28 words

The cellular telephone claimed in claim 1, further comprising: a protected random access memory; wherein the hash calculation is performed in conjunction with the protected random access memory.

Claim 10

Dependent Claim 23 words

The cellular telephone claimed in claim 8, further comprising security logic, wherein the security logic supervises access to the protected random access memory.

Claim 11

Dependent Claim 22 words

The cellular telephone claimed in claim 1, wherein the valid hash value is authenticated using a public key stored within the memory.

Claim 12

Dependent Claim 21 words

The cellular telephone claimed in claim 1, wherein the valid hash value is given a digital signature using a private key.

Claim 13

Dependent Claim 30 words

The cellular telephone claimed in claim 10, wherein a public/private key system is used that is selected from the group of algorithms consisting of: ELGAMAL, RSA, DSA, Fiege-Fiat-Shamir, and Fiat-Shamir.

Claim 14

Dependent Claim 33 words

The cellular telephone claimed in claim 1, wherein the hash calculation performed is selected from the group of hash functions consisting of: Snerfu, H-Hash, MD2, MD4, MD5, Secure Hash Algorithm (SHA), and HAVAL.

Claim 15

Dependent Claim 101 words

In a cellular telephone, a method for detecting memory tampering, the method comprising the steps of: storing a signed valid hash value produced by performing a hash calculation on selected contents of a memory which memory selected contents are known to be authentic; producing an audit hash value by performing the hash calculation on the selected contents of the memory; and comparing the audit hash value to the valid hash value, whereby a difference between the audit and the valid hash values indicates alteration of the selected memory contents, wherein the steps of storing, producing, and comparing are secure from tampering.

Claim 16

Dependent Claim 101 words

In a cellular telephone, a method for detecting memory tampering, the method comprising the steps of: storing a signed valid hash value produced by performing a hash calculation on selected contents of a memory which memory selected contents are known to be authentic; producing an audit hash value by performing the hash calculation on the selected contents of the memory; and comparing the audit hash value to the valid hash value, whereby a difference between the audit and the valid hash values indicates alteration of the selected memory contents, wherein the steps of storing, producing, and comparing are secure from tampering.

Claim 17

Dependent Claim 25 words

The method claimed in claim 14, wherein the step of producing the audit hash value is performed in conjunction with a protected random access memory.

Claim 18

Dependent Claim 25 words

The method claimed in claim 14, further including the step of: signing the valid hash value with a digital signature based on a private key.

Claim 19

Dependent Claim 27 words

The method claimed in claim 14, wherein the steps of producing the audit hash value and of comparing The audit and valid hash values are performed periodically.

Claim 20

Dependent Claim 25 words

The method claimed in claim 14, wherein the step of producing the audit hash value is performed pursuant to the expiration of a hardware-based timer.

Claim 21

Dependent Claim 21 words

The method claimed in claim 14, wherein the step of producing the audit hash value involves calculating audit hash value segments.

Claim 22

Dependent Claim 29 words

The method claimed in claim 19, wherein calculation of an audit hash value segment can be delayed as necessary while other processes occurring within the cellular telephone are completed.

Claim 23

Dependent Claim 43 words

The method claimed in claim 14, wherein the valid hash value is given a digital signature, and wherein the step of comparing the audit hash value to the valid hash value includes the step of authenticating the valid hash value against the signature.

Claim 24

Dependent Claim 99 words

In a cellular telephone, an apparatus comprising: a microprocessor; a flash memory whose contents include operating instructions for the cellular telephone; and an electronically erasable programmable read-only memory (EEPROM) whose contents include a valid hash value derived by performing a one-way hash calculation over selected portions of authentic flash and EEPROM memory contents; wherein the microprocessor periodically generates an audit hash value by performing the hash calculation over the selected portions, which audit hash value is compared to the authenticated valid hash value to assess whether at least one of the flash and the EEPROM memories have been altered.

Claim 25

Dependent Claim 99 words

In a cellular telephone, an apparatus comprising: a microprocessor; a flash memory whose contents include operating instructions for the cellular telephone; and an electronically erasable programmable read-only memory (EEPROM) whose contents include a valid hash value derived by performing a one-way hash calculation over selected portions of authentic flash and EEPROM memory contents; wherein the microprocessor periodically generates an audit hash value by performing the hash calculation over the selected portions, which audit hash value is compared to the authenticated valid hash value to assess whether at least one of the flash and the EEPROM memories have been altered.

Claim 26

Dependent Claim 29 words

The apparatus claimed in claim 22, wherein the one-way hash calculation is selected from the group consisting of: Snerfu, H-Hash, MD2, MD4, MD5, Secure Hash Algorithm (SHA), and HAVAL.

Claim 27

Dependent Claim 40 words

The apparatus claimed in claim 22, wherein the valid hash value receives a digital signature by a private key prior to being stored, and is authenticated by a public key for the purpose of comparison with the audit hash value.

Claim 28

Dependent Claim 27 words

The apparatus claimed in claim 24, wherein a public/private key system used is selected from the group of algorithms consisting of: ELGAMAL, RSA, DSA, Fiege-Fiat-Shamir, and Fiat-Shamir.

Claim 29

Dependent Claim 27 words

The apparatus claimed in claim 24, wherein the valid hash value receives a digital signature by the private key using processing means external to the cellular telephone.

Claim 30

Independent Claim 114 words

A system for preventing unauthorized access to a cellular telephone memory programming capability, the system comprising: a cellular telephone, including a memory for storing data, and a microprocessor having a means for authentication; and a data transfer device including signature means for supplying a signed message to the cellular mobile telephone; wherein the cellular telephone microprocessor assesses the authenticity of the data transfer device based upon an analysis of a signed message supplied by the data transfer device via a first port and a second port of a general purpose computer, wherein the data transfer device is attachable to the first port, and the second port is used to interface with the cellular telephone.

Claim 31

Independent Claim 114 words

A system for preventing unauthorized access to a cellular telephone memory programming capability, the system comprising: a cellular telephone, including a memory for storing data, and a microprocessor having a means for authentication; and a data transfer device including signature means for supplying a signed message to the cellular mobile telephone; wherein the cellular telephone microprocessor assesses the authenticity of the data transfer device based upon an analysis of a signed message supplied by the data transfer device via a first port and a second port of a general purpose computer, wherein the data transfer device is attachable to the first port, and the second port is used to interface with the cellular telephone.

Claim 32

Independent Claim 110 words

A method for assessing the authenticity of a cellular telephone programming device, the method comprising the steps of: sending a challenge message in response to a programming request via a first port and a second port of a general purpose computer, wherein the cellular telephone programming device is attachable to the first port, and the second port is used to interface with the cellular telephone; signing the challenge message in the cellular telephone programming device; sending the signed challenge message to the cellular telephone; authenticating the challenge message within the cellular telephone; and rejecting the cellular telephone programming device if the challenge message is not received by the authentication step.

Claim 33

Independent Claim 110 words

A method for assessing the authenticity of a cellular telephone programming device, the method comprising the steps of: sending a challenge message in response to a programming request via a first port and a second port of a general purpose computer, wherein the cellular telephone programming device is attachable to the first port, and the second port is used to interface with the cellular telephone; signing the challenge message in the cellular telephone programming device; sending the signed challenge message to the cellular telephone; authenticating the challenge message within the cellular telephone; and rejecting the cellular telephone programming device if the challenge message is not received by the authentication step.

Claim 34

Dependent Claim 147 words

In a system comprising a data transfer device for programming a cellular telephone, a method for preventing unauthorized access to memory in the cellular telephone, said method comprising the steps of: sending a programming request from the data transfer device to the cellular telephone via a first port and a second port of a general purpose computer, wherein the data transfer device is attachable to the first port, and the second port is used to interface with the cellular telephone; sending a challenge message from the cellular telephone to the data transfer device in response to the programming request; signing a challengeresponse message within the data transfer device; sending the signed challenge response message to the cellular telephone; authenticating the challenge response message within the cellular telephone; and entering a programming miode if authentication of the signal challenge response message confirms authenticity of the data transfer device.

Claim 35

Dependent Claim 147 words

In a system comprising a data transfer device for programming a cellular telephone, a method for preventing unauthorized access to memory in the cellular telephone, said method comprising the steps of: sending a programming request from the data transfer device to the cellular telephone via a first port and a second port of a general purpose computer, wherein the data transfer device is attachable to the first port, and the second port is used to interface with the cellular telephone; sending a challenge message from the cellular telephone to the data transfer device in response to the programming request; signing a challengeresponse message within the data transfer device; sending the signed challenge response message to the cellular telephone; authenticating the challenge response message within the cellular telephone; and entering a programming miode if authentication of the signal challenge response message confirms authenticity of the data transfer device.

Claim 36

Independent Claim 110 words

A system for programming a cellular telephone, the system comprising: a programmer; a general purpose computer having a first and a second port; wherein the programmer is attachable to the first port, and the second port is used to interface with a cellular telephone to be programmed, wherein in response to a request to program the cellular telephone received from the programmer, the cellular telephone returns a challenge which challenge is signed by the programmer and returned to the cellular telephone for authentication, whereby recovery of the challenge through authentication of the signed challenge is indicative of programmer authenticity and causes the cellular telephone to enter into a programming mode.

Claim 37

Independent Claim 110 words

A system for programming a cellular telephone, the system comprising: a programmer; a general purpose computer having a first and a second port; wherein the programmer is attachable to the first port, and the second port is used to interface with a cellular telephone to be programmed, wherein in response to a request to program the cellular telephone received from the programmer, the cellular telephone returns a challenge which challenge is signed by the programmer and returned to the cellular telephone for authentication, whereby recovery of the challenge through authentication of the signed challenge is indicative of programmer authenticity and causes the cellular telephone to enter into a programming mode.

Claim 38

Dependent Claim 39 words

The system of claim 30, wherein the cellular telephone comprises: a microprocessor, wherein in response to the request to program the cellular telephone received from the programmer, the microprocessor in the cellular telephone issues the challenge to the programmer.

Claim 39

Dependent Claim 67 words

In a cellular telephone, a system for preventing fraudulent memory access, comprising: security logic; a read only memory containing instruction code; protected random access memory; wherein the security logic prevents accesses to the protected random access memory by elements other than the read only memory; and a hardware-based timer, wherein the security logic prevents accesses to the hardware-based timer by elements other than the read only memory.

Claim 40

Dependent Claim 67 words

In a cellular telephone, a system for preventing fraudulent memory access, comprising: security logic; a read only memory containing instruction code; protected random access memory; wherein the security logic prevents accesses to the protected random access memory by elements other than the read only memory; and a hardware-based timer, wherein the security logic prevents accesses to the hardware-based timer by elements other than the read only memory.

Claim 41

Dependent Claim 35 words

The system claimed in claim 32, wherein accesses to the protected random access memory pursuant to instruction code in the read only memory can only take place when the system is in a supervisory mode.

Claim 42

Dependent Claim 59 words

An electronic device comprising: a microprocessor; and a memory; wherein the microprocessor performs a hash calculation on contents of the memory to derive an audit hash value, which audit hash value is compared to a valid hash value previously derived from performance of the hash calculation on authentic memory contents, said hash calculation and comparison being secure from tampering.

Claim 43

Dependent Claim 59 words

An electronic device comprising: a microprocessor; and a memory; wherein the microprocessor performs a hash calculation on contents of the memory to derive an audit hash value, which audit hash value is compared to a valid hash value previously derived from performance of the hash calculation on authentic memory contents, said hash calculation and comparison being secure from tampering.

Claim 44

Dependent Claim 22 words

The electronic device claimed in claim 34, wherein the audit hash value is periodically derived and compared to the valid hash value.

Claim 45

Dependent Claim 15 words

The electronic device claimed in claim 35, wherein the selected contents include microprocessor programming code.

Claim 46

Dependent Claim 17 words

The electronic device claimed in claim 34, wherein the memory includes a flash memory and an EEPROM.

Claim 47

Dependent Claim 24 words

The electronic device claimed in claim 37, wherein the audit hash value derived based on selected contents of the flash memory and the EEPROM.

Claim 48

Dependent Claim 22 words

The electronic device claimed in claim 34, wherein the valid hash value is authenticated using a public key stored within the memory.

Claim 49

Dependent Claim 21 words

The electronic device claimed in claim 34, wherein the valid hash value is given a digital signature using a private key.

Claim 50

Dependent Claim 30 words

The electronic device claimed in claim 40, wherein a public/private key system used is selected from the group of public key algorithms consisting of: ELGAMAL, RSA, DSA, Fiege-Fiat-Shamir, and Fiat-Shamir.

Claim 51

Dependent Claim 33 words

The electronic device claimed in claim 34, wherein the hash calculation performed is selected from the group of hash functions consisting of: Snerfu, H-Hash, MD2, MD4, MD5, Secure Hash Algorithm (SHA), and HAVAL.

Claim 52

Dependent Claim 101 words

In an electronic device, a method for detecting memory tampering, the method comprising the steps of: storing a signed valid hash value produced by performing a hash calculation on selected contents of a memory which memory selected contents are known to be authentic; producing an audit hash value by performing the hash calculation on the selected contents of the memory; and comparing the audit hash value to the valid hash value, whereby a difference between the audit and the valid hash values indicates alteration of the selected memory contents, wherein the steps of storing, producing, and comparing are secure from tampering.

Claim 53

Dependent Claim 101 words

In an electronic device, a method for detecting memory tampering, the method comprising the steps of: storing a signed valid hash value produced by performing a hash calculation on selected contents of a memory which memory selected contents are known to be authentic; producing an audit hash value by performing the hash calculation on the selected contents of the memory; and comparing the audit hash value to the valid hash value, whereby a difference between the audit and the valid hash values indicates alteration of the selected memory contents, wherein the steps of storing, producing, and comparing are secure from tampering.

Claim 54

Dependent Claim 25 words

The method claimed in claim 43, further including the step of: signing the valid hash value with a digital signature based on a private key.

Claim 55

Dependent Claim 27 words

The method claimed in claim 43, wherein the steps of producing the audit hash value and of comparing the audit and valid hash values are performed periodically.

Claim 56

Dependent Claim 21 words

The method claimed in claim 43, wherein the step of producing the audit hash value involves calculating audit hash value segments.

Claim 57

Dependent Claim 29 words

The method claimed in claim 46, wherein calculation of an audit hash value segment can be delayed as necessary while other processes occurring within the electronic device are completed.

Claim 58

Dependent Claim 43 words

The method claimed in claim 43, wherein the valid hash value is given a digital signature, and wherein the step of comparing the audit hash value to the valid hash value includes the step of authenticating the valid hash value against the signature.

Claim 59

Independent Claim 64 words

A system for preventing memory access, said system comprising: security logic a read only memory containing instruction code; protected random access memory; wherein the security logic prevents accesses to the protected random access memory by elements other than the read only memory; and a hardware-based timer, wherein the security logic prevents accesses to the hardware-based timer by elements other than the read only memory.

Claim 60

Independent Claim 64 words

A system for preventing memory access, said system comprising: security logic a read only memory containing instruction code; protected random access memory; wherein the security logic prevents accesses to the protected random access memory by elements other than the read only memory; and a hardware-based timer, wherein the security logic prevents accesses to the hardware-based timer by elements other than the read only memory.

Claim 61

Dependent Claim 35 words

The system claimed in claim 49, wherein accesses to the protected random access memory pursuant to instruction code in the read only memory can only take place when the system is in a supervisory mode.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2003-02-14	2003-08-16	2004-02-15	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2007-02-14	2007-08-16	2008-02-15	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2011-02-14	2011-08-16	2012-02-15	$7700.00	Window Closed / Lapsed

System for preventing electronic memory tampering

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