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US5633931A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for calculating message signatures in advance

Assignee: EMC Corp
•
Filing: 1995-06-30
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Granted: 1997-05-27
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Expires: 2015-06-30
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Abstract

Abstract The present invention provides an improved method and apparatus for authenticating message packets to prevent forgery thereof. A server processes a client request and generates a response message. A message signature, which is generated using the session key and the message itself, is appended to the message to create an appended message. The server sends the appended message to the client. At the same time that the server works on the client request, the client predicts the response message and calculates a predicted message signature based on the session key and the predicted message. After receiving the appended message, the client strips the message signature from the appended message and compares it to the predicted message signature. If the two signatures match, the received message packet is authenticated.

Inventors

  • 👤 Jimmy J. Wright

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 19:10
CPC Classifications
H; H04; H04L; H04L9/00; H04L9/32; H04L9/3247

Claims Analysis

Total Claims: 26
Claim 1
Independent Claim 119 words
A method for authenticating a message transmitted from a sender to a receiver, comprising the steps of: a) generating at the sender a message signature; b) sending from the sender to the receiver the message signature and a message; c) generating at the receiver, prior to receiving the message signature and message from the sender, a predicted message signature that is likely to be transmitted from the sender to the receiver; d) receiving at the receiver the message signature and message transmitted by the sender; e) comparing at the receiver the predicted message signature with the received message signature; and f) authenticating the message received by the receiver if the predicted message signature and the received message signature match.
Claim 2
Independent Claim 119 words
A method for authenticating a message transmitted from a sender to a receiver, comprising the steps of: a) generating at the sender a message signature; b) sending from the sender to the receiver the message signature and a message; c) generating at the receiver, prior to receiving the message signature and message from the sender, a predicted message signature that is likely to be transmitted from the sender to the receiver; d) receiving at the receiver the message signature and message transmitted by the sender; e) comparing at the receiver the predicted message signature with the received message signature; and f) authenticating the message received by the receiver if the predicted message signature and the received message signature match.
Claim 3
Dependent Claim 15 words
A method as recited in claim 1, wherein the sender and receiver are digital computers.
Claim 4
Dependent Claim 22 words
A method as recited in claim 2, wherein the sender and receiver are a server and client, respectively, in a computer network.
Claim 5
Dependent Claim 23 words
A method as recited in claim 1, wherein the message is a response to a prior communication from the receiver to the sender.
Claim 6
Dependent Claim 17 words
A method as recited in claim 3, wherein the message is a completion code or connection status.
Claim 7
Dependent Claim 23 words
A method as recited in claim 1, wherein the message signature generated by the sender is at least partially derived from the message.
Claim 8
Dependent Claim 24 words
A method as recited in claim 1, wherein the message signature generated by the receiver is at least partially derived from an expected message.
Claim 9
Dependent Claim 38 words
A method as recited in claim 1, wherein the message signature generated by the sender and the message signature generated by the receiver are at least partially derived from a code held by both the sender and receiver.
Claim 10
Dependent Claim 14 words
A method as recited in claim 7, wherein the code is the session key.
Claim 11
Dependent Claim 24 words
A method as recited in claim 1, wherein the message signatures generated by the sender and the receiver are derived from a digest algorithm.
Claim 12
Dependent Claim 34 words
A method as recited in claim 1, wherein in step b) the sender appends the message signature to the message to form an appended message which is sent from the sender to the receiver.
Claim 13
Independent Claim 150 words
A method for authenticating a message transmitted from a sender to a receiver, comprising the steps of: a) generating at the sender a message signature at least partially derived from a message and a code held by both the sender and receiver; b) sending from the sender to the receiver the message signature and a message; c) generating at the receiver, prior to receiving the message signature and message from the sender, a predicted message signature that is at least partially derived from an expected message from the sender to the receiver and a code held by both the sender and receiver; d) receiving at the receiver the message signature and message transmitted by the sender; e) comparing at the receiver the predicted message signature with the received message signature; and f) authenticating the message received by the receiver if the predicted message signature and the received message signature match.
Claim 14
Independent Claim 150 words
A method for authenticating a message transmitted from a sender to a receiver, comprising the steps of: a) generating at the sender a message signature at least partially derived from a message and a code held by both the sender and receiver; b) sending from the sender to the receiver the message signature and a message; c) generating at the receiver, prior to receiving the message signature and message from the sender, a predicted message signature that is at least partially derived from an expected message from the sender to the receiver and a code held by both the sender and receiver; d) receiving at the receiver the message signature and message transmitted by the sender; e) comparing at the receiver the predicted message signature with the received message signature; and f) authenticating the message received by the receiver if the predicted message signature and the received message signature match.
Claim 15
Dependent Claim 15 words
A method as recited in claim 12, wherein the sender and receiver are digital computers.
Claim 16
Dependent Claim 22 words
A method as recited in claim 13, wherein the sender and receiver are a server and client, respectively, in a computer network.
Claim 17
Dependent Claim 23 words
A method as recited in claim 12, wherein the message is a response to a prior communication from the receiver to the sender.
Claim 18
Dependent Claim 17 words
A method as recited in claim 12, wherein the message is a completion code or connection status.
Claim 19
Dependent Claim 21 words
A method as recited in claim 12, wherein the code held by both the sender and receiver is the session key.
Claim 20
Dependent Claim 30 words
A method as recited in claim 12, wherein the message signature generated by the sender and the predicted message signature generated by the receiver are derived from a digest algorithm.
Claim 21
Dependent Claim 34 words
A method as recited in claim 12, wherein in step b) the sender appends the message signature to the message to form an appended message which is sent from the sender to the receiver.
Claim 22
Independent Claim 177 words
A method for authenticating a message transmitted from a sender to a receiver, where the message is a response to a prior communication from the receiver to the sender, comprising the steps of: a) generating at the sender a message signature at least partially derived from a message and a code held by both the sender and receiver; b) creating at the sender an appended message by combining the message signature to the message; c) sending from the sender to the receiver the appended message; d) generating at the receiver, prior to receiving the message signature and message from the sender, a predicted message signature that is at least partially derived from an expected message from the sender to the receiver and a code held by both the sender and receiver; e) receiving at the receiver the appended message transmitted by the sender; f) comparing at the receiver the predicted message signature with the received message signature; and g) authenticating the message received by the receiver if the predicted message signature and the received message signature match.
Claim 23
Independent Claim 177 words
A method for authenticating a message transmitted from a sender to a receiver, where the message is a response to a prior communication from the receiver to the sender, comprising the steps of: a) generating at the sender a message signature at least partially derived from a message and a code held by both the sender and receiver; b) creating at the sender an appended message by combining the message signature to the message; c) sending from the sender to the receiver the appended message; d) generating at the receiver, prior to receiving the message signature and message from the sender, a predicted message signature that is at least partially derived from an expected message from the sender to the receiver and a code held by both the sender and receiver; e) receiving at the receiver the appended message transmitted by the sender; f) comparing at the receiver the predicted message signature with the received message signature; and g) authenticating the message received by the receiver if the predicted message signature and the received message signature match.
Claim 24
Dependent Claim 15 words
A method as recited in claim 20, wherein the sender and receiver are digital computers.
Claim 25
Dependent Claim 22 words
A method as recited in claim 21, wherein the sender and receiver are a server and client, respectively, in a computer network.
Claim 26
Dependent Claim 21 words
A method as recited in claim 20, wherein the code held by both the sender and receiver is the session key.

References Cited (Backward Citations)

US4393269A Cited
US4881264A Cited
US4947430A Cited
US5442645A Cited
US5231668A Cited
US5349642A Cited
US5475763A Cited
US5371794A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-05-26 2000-11-25 2001-05-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-05-26 2004-11-25 2005-05-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-05-26 2008-11-25 2009-05-27 $7700.00 Window Closed / Lapsed

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