EP0223122A2
Expired / Lapsed
EP
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Secure component authentication system
Assignee: International Business Machines Corp
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Filing: 1986-10-28
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Granted: —
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Expires: 2006-10-28
Abstract
Abstract A system for authenticating components in a communications system using cryptographic techniques to determine if each has the proper key without disclosing information which would be useful to an impostor in deriving the key. A random number (32) generated at a first terminal is encrypted under its key (K1) for transmission as a first value (X) to a second terminal whose identity is to be authenticated. The second terminal decrypts the transmitted first value using its key (K2) deriving a second value (which equals the random number if the keys are identical.) The second terminal then encrypts its key using the second value as the key, generating a third (Z) value which is transmitted back to the first terminal for verification. The first terminal then verifies the third value, either by decrypting it using the random number as the key to obtain its key or by encrypting its key using the random number as key to derive the third number (if the two keys are identical.) Optionally, roles of the two terminals are then reversed after the second terminal has been identified, allowing the second terminal to authenticate the first terminal.
Inventors
- 👤 Dennis George Abraham
- 👤 Glen Paul Double
- 👤 Steven William Neckyfarow
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 16:28
CPC Classifications
H; H04; H04L; H04L63/00; H04L63/08; H04L63/0869; H04L9/00; H04L9/32; H04L9/3271
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
166 words
A method whereby a first terminal (20) may authenticate a second terminal (10) wherein the terminals each posses an encryption key (K1,K2) and the second terminal is authenticated if the encryption keys are equal, the steps of the method comprising: generating a first number (RN) at the first terminal and creating a second number (X) by encrypting the first number using the encryption key K1 of the first terminal; transmitting the second number to the second terminal; generating a third number (Y) at the second terminal by decryping the second number using the encryption key (K2) of the second terminal; generating a fourth number (Z) at the second terminal by encrypting the encryption key of the second terminal using the third number as the key; transmitting the fourth number to the first terminal; and verifying at said first terminal that said fourth number equals the encryption of said encryption key of said first terminal using said first number as key to thereby authenticate said second terminal.
Claim 2
Independent Claim
166 words
A method whereby a first terminal (20) may authenticate a second terminal (10) wherein the terminals each posses an encryption key (K1,K2) and the second terminal is authenticated if the encryption keys are equal, the steps of the method comprising: generating a first number (RN) at the first terminal and creating a second number (X) by encrypting the first number using the encryption key K1 of the first terminal; transmitting the second number to the second terminal; generating a third number (Y) at the second terminal by decryping the second number using the encryption key (K2) of the second terminal; generating a fourth number (Z) at the second terminal by encrypting the encryption key of the second terminal using the third number as the key; transmitting the fourth number to the first terminal; and verifying at said first terminal that said fourth number equals the encryption of said encryption key of said first terminal using said first number as key to thereby authenticate said second terminal.
Claim 3
Dependent Claim
71 words
A method of authenticating a terminal including the steps of Claim 1 wherin the step of verifying includes the step of generating at the first terminal a fifth number (B) which is the encryption of its encryption key using the first number as key, and comparing said fifth number with the fourth number, thereby determining said second terminal used an encryption key equal to the encryption key of said first terminal.
Claim 4
Dependent Claim
65 words
A method of authenticating a terminal including the steps of Claim 1 wherein the step of verifying includes the steps of decrypting the fourth number (Z) using the first number of the first terminal to obtain a fifth value, comparing said fifth value to the first number, and authenticating the second terminal if and only if said fifth number and said first number are equal.
Claim 5
Dependent Claim
25 words
A method of authenticating a terminal including the steps of Claim 1 wherein the step of generating a first number includes generating a random number.
Claim 6
Dependent Claim
30 words
A method of authenticating a terminal including the steps of Claim 4 and further including the use of the random number in communication between terminals after authentication has been completed.
Claim 7
Dependent Claim
46 words
A method of authenticating a terminal wherein, after the first terminal authenticates the second terminal using the steps of Claim 1, the second terminal authenticates the first terminal using the role of the first terminal while the first terminal assumes the role of the second terminal.
Claim 8
Independent Claim
165 words
A method whereby a first terminal determines whether a second terminal is using the same encryption key, the steps of the method comprising: transmitting from said first terminal to said second terminal a first value representing the encryption of a secret value under the first terminal's encryption key; deriving at the second terminal a second value by decrypting the first value using the second terminal's encryption key; transmitting from said second terminal to said first terminal a third value representing the secret key encrypted using the second value as key; and verifying at the first terminal that said third value represents the decryption of said first value using the first terminal's key forming an intermediate result followed by encryption of the first terminal's key using the intermediate result as key to verify that the first and second terminal have the same keys, whereby authentication of the second terminal occurs if and only if the encryption keys used by said first and second terminals are equal.
Claim 9
Independent Claim
165 words
A method whereby a first terminal determines whether a second terminal is using the same encryption key, the steps of the method comprising: transmitting from said first terminal to said second terminal a first value representing the encryption of a secret value under the first terminal's encryption key; deriving at the second terminal a second value by decrypting the first value using the second terminal's encryption key; transmitting from said second terminal to said first terminal a third value representing the secret key encrypted using the second value as key; and verifying at the first terminal that said third value represents the decryption of said first value using the first terminal's key forming an intermediate result followed by encryption of the first terminal's key using the intermediate result as key to verify that the first and second terminal have the same keys, whereby authentication of the second terminal occurs if and only if the encryption keys used by said first and second terminals are equal.
Claim 10
Dependent Claim
37 words
A method of the type described in Claim 7 wherein the intermediate result in the verifying step equals said secret value and said second value if the encryption keys of said first and second terminals are equal.
Claim 11
Dependent Claim
74 words
A secure encryption system wherein a first terminal challenges a second terminal which responds with a response based upon the challenge, the improvement wherein the second terminal includes means for decrypting the challenge using its key and means for encrypting its key using the decrypted challenge as key to generate its response and the first terminal includes means for performing similar steps using its key and the challenge in order to verify the response.
Claim 12
Dependent Claim
74 words
A secure encryption system wherein a first terminal challenges a second terminal which responds with a response based upon the challenge, the improvement wherein the second terminal includes means for decrypting the challenge using its key and means for encrypting its key using the decrypted challenge as key to generate its response and the first terminal includes means for performing similar steps using its key and the challenge in order to verify the response.
References Cited (Backward Citations)
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