Patents by Inventor Sarvar Patel

Sarvar Patel has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20030191950
    Abstract: A hash function is applied to a prefix of a VIL input. The output is added to a suffix of the input. A block cipher is applied to results of the addition. An encryption function is performed on the prefix. The final output is the output of the block cipher and the encryption function. In a second encryption technique, a hash function is applied to an input, and the output of the hash function has first and second portions. A block cipher is applied to the second portion. The output of the block cipher is added to the first portion, and a second function is applied to the result of this first addition. The output of the second function is added to the second portion. An inverse hash function is then applied to the output of the first and second additions, creating an encrypted output.
    Type: Application
    Filed: March 28, 2002
    Publication date: October 9, 2003
    Inventors: Sarvar Patel, Zulfikar Amin Ramzan, Ganapathy Subramanian Sundaram
  • Patent number: 6591364
    Abstract: In the method for establishing a session key, a network and a mobile transfer codes between one another. The mobile and the network perform mutual authentication based on the codes. Besides performing this mutual authentication, the mobile and the network to establish the session key based on the codes. In one embodiment, the messages forming part of the intended session are sent with the codes, and form a basis upon which the codes for authentication have been derived.
    Type: Grant
    Filed: August 28, 1998
    Date of Patent: July 8, 2003
    Assignee: Lucent Technologies Inc.
    Inventor: Sarvar Patel
  • Patent number: 6463154
    Abstract: In the method for managing the use of temporary mobile identifiers (TIDs), the mobile and the network each store a list of TIDs for the mobile. Newly determined TIDs are added to the respective TID list such that the TIDs are stored in chronological order. To determine a new TID, the network sends a first challenge to the mobile and the mobile sends a second challenge to the network as part of a TID update protocol. The network and the mobile then determine the new TID based on the first and second challenges. As communication between the mobile and the network continues, the respective TID lists are updated. Namely, when either the network or the mobile confirms a TID, the TIDs older than the confirmed TID are deleted from the TID list. In communicating with one another, the mobile will use the oldest TID on its TID list, while the network will use the newest TID on its TID list.
    Type: Grant
    Filed: August 28, 1998
    Date of Patent: October 8, 2002
    Assignee: Lucent Technologies Inc.
    Inventor: Sarvar Patel
  • Publication number: 20020071558
    Abstract: The present invention is a key conversion system for deterministically and reversibly converting a first key value of a first communications system into a second key value of a second communication system. For example, the key conversion system generates a first intermediate value from at least a portion of the first key value using a first random function. At least a portion of the first intermediate value is provided to a second random function to produce a second value. An exclusive-or is performed on at least a portion of the first key value and at least a portion of the second value to generate a second intermediate value. At least a portion of the second intermediate value is provided to a third random function to produce a third value.
    Type: Application
    Filed: December 11, 2000
    Publication date: June 13, 2002
    Inventor: Sarvar Patel
  • Patent number: 6374355
    Abstract: In the method for securing over-the-air communication in wireless system, a mobile sends a system access request and dummy data associated with the system access request to a network. The network sends a first data stream including a first data portion to the mobile in response to the system access request and the dummy data. The mobile extracts the first data portion from the first bit stream, and sends a second bit stream to the network. The second bit stream includes a second data portion. The mobile and the network both generate a key based on the first data portion and the second data portion, and establish a first encrypted and authenticated communication channel in cooperation using the key. The mobile then transfers authorizing information to the network over the first encrypted and authenticated communication channel. If accepted, a second encrypted and authenticated communication channel is established.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: April 16, 2002
    Assignee: Lucent Technologies Inc.
    Inventor: Sarvar Patel
  • Patent number: 6285761
    Abstract: The present invention is a method for outputting larger bit size pseudo-random number zi that is cryptographically secure. Since larger bit size pseudo-random numbers are being outputted, larger bit size segments of messages may be encrypted resulting in a speedier encryption process than encryption processes of the prior art. In one embodiment, the present invention is a pseudo-random number generator defined by a modular exponential function xi=gxi−1 mod p. The output of the pseudo-random number generator being a pseudo-random number zi comprising a j−1 bit size segment of xi. The value of j being less than or equal to m−2c (i.e., j≦m−2c). In an embodiment of the present invention, the pseudo-random number zi includes the j least significant bits of xi excluding the least significant bit of xi.
    Type: Grant
    Filed: March 4, 1998
    Date of Patent: September 4, 2001
    Assignee: Lucent Technologies, Inc.
    Inventors: Sarvar Patel, Ganapathy Subramanian Sundaram
  • Patent number: 6249867
    Abstract: In the method for transferring sensitive information using unsecured communication, a first party receives a public key of a second party, produces an encryption result by performing keyed encryption on at least a first random number using the public key, and transfers the encryption result to the second party over an unsecured communication channel. The second party decrypts the encryption result to obtain the first random number. Authorizing information is then transferred from the first party to the second party over a first encrypted and authenticated communication channel established using the first random number. Sensitive information is further transferred from the second party to the first party over a second encrypted and authenticated communication channel established using the first random number if the second party accepts the authorizing information.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: June 19, 2001
    Assignee: Lucent Technologies Inc.
    Inventor: Sarvar Patel
  • Patent number: 6243811
    Abstract: In the method for updating secret shared data (SSD) in a wireless communication system, a first party outputs a first random number as a first challenge wherein the first party is one of a network and a mobile. A second party generates a second random number in response to the first challenge. The second party is the mobile if the first party is the network, and the second party is the network if the first party is the mobile. The second party generates a first challenge response by performing a keyed cryptographic function (KCF) on the first challenge and the second random number using a secondary key, which is not the SSD and is derived from a root key. The second party then transfers the second random number, as a second challenge, and the first challenge response to the first party.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: June 5, 2001
    Assignee: Lucent Technologies Inc.
    Inventor: Sarvar Patel
  • Patent number: 6192474
    Abstract: In the password protocol, the communicating parties exchange calculation results, which each include an exponential, to generate a key. In generating the calculation results, each party adds the password to their respective exponential. If the authorizing information previously sent by one party is acceptable to the other party, then this other party uses the key established according to the password protocol. The channel authorizing information is sent over a secure communication channel. The secure communication channel is also used in other embodiments to verify a hash on at least one calculation result sent between the parties. If the hash is verified, then a key is established using the calculation results sent between the parties.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: February 20, 2001
    Assignee: Lucent Technologies Inc.
    Inventors: Sarvar Patel, Adam L. Berenzweig
  • Patent number: 6118993
    Abstract: The present invention strengthens authentication protocols by making it more difficult for handset impersonators to perform call origination using replay attacks. The present invention accomplishes this goal by using the most significant digits of a telephone number being dialed as a parameter for determining authentication codes. Using the most significant digits makes it more difficult for impersonators to successfully use replay attacks on call origination, wherein the replay attacks involve the appendage of digits to a telephone number to be dialed.
    Type: Grant
    Filed: January 5, 1998
    Date of Patent: September 12, 2000
    Assignee: Lucent Technologies, Inc.
    Inventor: Sarvar Patel
  • Patent number: 6014085
    Abstract: The invention strengthens authentication protocols by making it more difficult for handset impersonators to gain system access using replay attacks. This goal is accomplished using challenge codes as a parameter for determining authentication codes, whereby different challenge codes cause different authentication codes to be generated. In one embodiment, the challenge codes are functions of challenge types (e.g., global or unique challenges) and/or handset states (e.g., call origination, page response, registration, idle, and SSD-A update). This embodiment prevents handset impersonators from successfully utilizing replay attacks to impersonate a legitimate handset if the legitimate handset is in a different state than the handset impersonator, or if the legitimate handset is responding to a different challenge type than the handset impersonator.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: January 11, 2000
    Assignee: Lucent Technologies Inc.
    Inventor: Sarvar Patel