Authentication of remote appliance messages using an embedded cryptographic device

• US 20030001721A1
• Filed: 12/27/2000
• Published: 01/02/2003
• Est. Priority Date: 07/18/2000
• Status: Active Grant

• Current Assignee: Haier US Appliance Solutions, Inc. DBA GE Appliances (Haier Group Company)
• Original Assignee: General Electric Company
• Inventors: Hershey, John Erik, Evans, Scott Charles, Daum, Wolfgang
• Granted Patent: US 7,234,062 B2
• Time in Patent Office: Days
• US Class Current: 340/5.8
• CPC Class Codes: H04L 12/2803 Home automation networks
• CPC Class Codes: H04L 12/2818 from a device located outside both the home and the home network access arrangements H04L12/2856; for remote control or remote monitoring of applications H04L67/025; arrangements for transmitting signals characterised by the use of a wireless eletrical link G08C17/00; telephonic communication systems adapted for combination with remote control systems H04M11/007
• CPC Class Codes: H04L 2012/2843 Mains power line
• CPC Class Codes: H04L 2012/285 Generic home appliances, e.g. refrigerators
• CPC Class Codes: H04L 67/125 involving control of end-device applications over a network
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04L 9/32 including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials

Abstract

A method for authenticating appliance messages sent between an appliance and an appliance communication center over an appliance communications network includes maintaining a shared message counter at both the appliance communication center. A shared message counter at both the appliance communication center and the remotely located appliance. An authentication algorithm is applied to the appliance message and the shared message counter to generate an authentication word. The appliance message is then transmitted to the appliance or the communication center along with the authentication word. Upon receiving the appliance message, the appliance or the communication center will apply an authentication algorithm to the appliance message and the shared counter to generate an authentication word. The generated authentication word may be compared to the word received with the appliance message to determine authenticity of the message.

Claims

1. A method for replacing an existing authentication keying variable K with a new authentication keying variable K′

generated from K, the method comprising;

generating a first authentication word, W₁, based on the existing keying variable K, a counter, C, and a master keying variable, KM;

selecting a portion of W₁ as a first-portion of K′

; and

completing remaining portions of K′

by iteratively;

generating new authentication words, W_n based on C, KM, and a concatenation of a prior authentication word and K; and

selecting an additional portion of W_n as an additional portion of K′

.

2. The method of claim 1, wherein generating new authentication words, W_n, comprises generating new authentication words based on C, KM, and a concatenation of an immediately prior authentication word W_n−

1 and K.

3. The method of claim 1, wherein K′

is different in length than K.

4. The method of claim 1, wherein K′

is equal in length to K.

5. The method of claim 1, further comprising receiving an authentication keying variable replacement message at an appliance.

6. The method of claim 1, wherein selecting a portion of W₁ comprises selecting 8-bits of W₁.

7. The method of claim 6, wherein selecting a portion of W₁ comprises selecting the first 8-bits of W₁.

8. The method of claim 1, wherein selecting an additional portion of W_n as an additional portion of K′

comprises selecting the first 8-bits of W_n as nth 8-bits of K′

.

9. A replacement authentication key generator comprising:

a processing circuit; and

a memory coupled to the processing circuit, the memory storing instructions for execution by the processing circuit for;

generating a first authentication word, W₁, based on the existing keying variable K, a counter, C, and a master keying variable, KM;

selecting a portion of W₁ as a first portion of K′

; and

completing remaining portions of K′

by iteratively;

generating new authentication words, W_n based on C, KM, and a concatenation of a prior authentication word and K; and

selecting an additional portion of W_n as an additional portion of K′

.

10. The replacement authentication key generator of claim 9, wherein the instructions for generating new authentication words, W_n, comprises generating new authentication words based on C, KM, and a concatenation of an immediately prior authentication word W_n−

1 and K.

11. The replacement authentication key generator of claim 9, wherein K′

is different in length than K.

12. The replacement authentication key generator of claim 9, wherein K′

is equal in length to K.

13. The replacement authentication key generator of claim 9, wherein the instructions for selecting a portion of W₁ comprises selecting 8-bits of W₁.

14. The replacement authentication key generator of claim 13, wherein the instructions for selecting a portion of W₁ comprises selecting the first 8-bits of W₁.

15. The replacement authentication key generator of claim 9, wherein the instructions for selecting an additional portion of W_n as an additional portion of K′

comprises selecting the first 8-bits of W_n as nth 8-bits of K′

.

17. The method of claim 16, further comprising:

receiving the authenticated message at the appliance;

applying the shared message counter, as stored in the appliance, and the appliance message to the authentication algorithm to generate a second authentication word; and

comparing the first authentication word and the second authentication word to determine authenticity of the authenticated message.

18. The method of claim 17, further comprising incrementing the shared message counter, as stored in the appliance, after receiving a genuine authenticated message at the appliance.

19. The method of claim 16, wherein applying comprises applying an authentication keying variable, K.

20. The method of claim 19, wherein applying comprises:

establishing a working register R, comprising at least bytes R0, R1, R2, R3;

initializing R3 to a directional code, representing a transmission from the appliance communication center to the appliance;

initializing at least R2, R1, and RO to the bytes C2, C1, and C0 of the shared message counter, as stored in the communication center, respectively;

iteratively performing, a first number of times, the steps of;

performing at least one arithmetic, logical and shifting operation on R;

shifting R; and

setting the first authentication word equal to the value contained in R.

21. The method of claim 20, wherein performing a transformation of R comprises iteratively performing, as many times as there are bytes in K, the steps of:

establishing an index, equal to the greater of;

a non-zero constant; and

a number of bytes in the message less one; and

iteratively performing, a number of times equal to the index plus one;

forming P as the dot product of R2 and RO;

forming Q as the bitwise exclusive or of P

with the constant expression ‘

01010101’

;

forming S by adding Q to K;

forming S′

by end around rotating S;

forming T as the bitwise exclusive or of S′ and

R3;

forming F as the bitwise exclusive or of T with a byte of the appliance message; and

replacing R3 with R2, R2 with R1, R1 with R0, and R0 with F.

22. The method of claim 21, wherein the non-zero constant is at least 3.

23. The method of claim 16, wherein maintaining comprises maintaining a separate shared counter for a plurality of appliances.

24. The method of claim 16, further comprising incrementing the shared message counter, as stored in the communication center, after transmitting the authenticated message to the appliance.

26. The appliance communication center of claim 25, wherein the instructions for maintaining comprises maintaining a separate shared counter for a plurality of appliances.

27. The appliance communication center of claim 25, wherein the instructions further comprise incrementing the shared message counter, as stored in the communication center, after transmitting the authenticated message to the appliance.

29. The appliance message authentication device of claim 28, wherein the instructions further comprise incrementing the shared message counter, as stored in the appliance, after receiving a genuine authenticated message at the appliance.

16. In an appliance communication network, a method for authenticating appliance messages, the method comprising:

maintaining at an appliance communication center a shared message counter, the shared message counter shared between the communication center and a remotely located appliance;

applying an appliance message and the shared message counter, as stored in the communication center, to an authentication algorithm to generate a first authentication word; and

transmitting the appliance message and the first authentication word as an authenticated message to the appliance.

25. An appliance communication center comprising:

network connections terminating at appliances;

a processing circuit;

a memory storing a plurality of shared counters, each shared counter shared between the communication center and an appliance, the memory further storing instructions for;

maintaining at an appliance communication center

a shared message counter, the shared message counter shared between the communication center and a remotely located appliance;

applying an appliance message and the shared message counter, as stored in the communication center, to an authentication algorithm to generate a first authentication word; and

transmitting the appliance message and the first authentication word as an authenticated message to the appliance.

28. In an appliance, an appliance message authentication device comprising:

a processor; and

a memory coupled to the processor, the memory storing instructions for execution by the processor for;

receiving the authenticated message at the appliance;

applying the shared message counter, as stored in the appliance, and the appliance message to the authentication algorithm to generate a second authentication word; and

comparing the first authentication word and the second authentication word to determine authenticity of the authenticated message.

30. In an appliance communication network, a method for authenticating appliance messages, the method comprising:

maintaining at an appliance a shared message counter, the shared message counter shared between the appliance and a remotely located appliance communication center;

applying an appliance message and the shared message counter, as stored in the appliance, to an authentication algorithm to generate a first authentication word; and

transmitting the appliance message and the first authentication word as an authenticated message to the appliance communication center.

31. The method of claim 30, further comprising:

receiving the authenticated message at the appliance communication center;

applying the shared message counter, as stored in the appliance communication center, and the appliance message to the authentication algorithm to generate a second authentication word; and

comparing the first authentication word and the second authentication word to determine authenticity of the authenticated message.