Patents by Inventor Sanguthevar Rajasekaran

Sanguthevar Rajasekaran 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).

  • Patent number: 8429720
    Abstract: A computer-representable object (including, without limitation, a cryptographic key, or a graph or a Boolean description of a system) is secured using a generalized camouflaging technique. The secured object need not be stored in the system, not even in encrypted form. Instead, the technique employs a composition function that regenerates the secured object when one inputs a valid password (which may be any computer-representable information held by a user). By regenerating the secured object each time a valid password is entered, there is no need to store the secured object. If one inputs an invalid password, the technique may generate an incorrect object, such that the user is unable to distinguish this incorrect object from the secured object. If the user tries to use the incorrect object, the user can be exposed as unauthorized, without the user's knowledge that he has been exposed.
    Type: Grant
    Filed: November 3, 2008
    Date of Patent: April 23, 2013
    Assignee: CA, Inc.
    Inventors: Sanguthevar Rajasekaran, Geoffrey R. Hird, Balas Natarajan Kausik
  • Patent number: 7634470
    Abstract: The present invention describes techniques for performing searches in an efficient manner while minimizing the memory resources required to perform the searches. According to the techniques of the present invention, the number of comparisons needed to determine if a query element is in included in a set of elements is proportional to the length of the query element and independent of the number of elements in the set of elements.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: December 15, 2009
    Assignee: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, Rajendra A. Gopalakrishna
  • Publication number: 20090138706
    Abstract: Techniques for efficiently searching encrypted searchable spaces. For example, embodiments of the present invention provide techniques for searching a plurality of files that are stored in encrypted (or ciphertext) form. According to embodiments of the present invention, the search can usually be performed by decrypting only a portion of the encrypted searchable space. According to an embodiment of the present invention, the search techniques determine a set of files comprising one or more files from the plurality of encrypted files that contain a user-specified query element. The set of files is usually determined by decrypting only a subset of the plurality of encrypted files.
    Type: Application
    Filed: December 7, 2008
    Publication date: May 28, 2009
    Applicant: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, Rammohan Varadarajan
  • Publication number: 20090138944
    Abstract: A computer-representable object (including, without limitation, a cryptographic key, or a graph or a Boolean description of a system) is secured using a generalized camouflaging technique. The secured object need not be stored in the system, not even in encrypted form. Instead, the technique employs a composition function that regenerates the secured object when one inputs a valid password (which may be any computer-representable information held by a user). By regenerating the secured object each time a valid password is entered, there is no need to store the secured object. If one inputs an invalid password, the technique may generate an incorrect object, such that the user is unable to distinguish this incorrect object from the secured object. If the user tries to use the incorrect object, the user can be exposed as unauthorized, without the user's knowledge that he has been exposed.
    Type: Application
    Filed: November 3, 2008
    Publication date: May 28, 2009
    Applicant: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, Geoffrey R. Hird, Balas Natarajan Kausik
  • Patent number: 7484092
    Abstract: Techniques for efficiently searching encrypted searchable spaces. For example, embodiments of the present invention provide techniques for searching a plurality of files that are stored in encrypted (or ciphertext) form. According to embodiments of the present invention, the search can usually be performed by decrypting only a portion of the encrypted searchable space. According to an embodiment of the present invention, the search techniques determine a set of files comprising one or more files from the plurality of encrypted files that contain a user-specified query element. The set of files is usually determined by decrypting only a subset of the plurality of encrypted files.
    Type: Grant
    Filed: March 11, 2002
    Date of Patent: January 27, 2009
    Assignee: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, Rammohan Varadarajan
  • Patent number: 7454782
    Abstract: A computer-representable object (including, without limitation, a cryptographic key, or a graph or a Boolean description of a system) is secured using a generalized camouflaging technique. The secured object need not be stored in the system, not even in encrypted form. Instead, the technique employs a composition function that regenerates the secured object when one inputs a valid password (which may be any computer-representable information held by a user). By regenerating the secured object each time a valid password is entered, there is no need to store the secured object. If one inputs an invalid password, the technique may generate an incorrect object, such that the user is unable to distinguish this incorrect object from the secured object. If the user tries to use the incorrect object, the user can be exposed as unauthorized, without the user's knowledge that he has been exposed.
    Type: Grant
    Filed: October 30, 2001
    Date of Patent: November 18, 2008
    Assignee: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, Geoffrey R. Hird, Balas Natarajan Kausik
  • Patent number: 7167565
    Abstract: An n person secret sharing solution computes n unique keys to be distributed to the secret owners along with an exponentiated version of the secret. The custodian performs an exponent/modulo operation each time one of the keys is received from one of the secret owners. Alternatively, n+1 keys are created by the custodian, and the custodian retains one key after distributing the remaining n keys to the secret owners. After the custodian has received and processed the n keys from the secret owners, he performs an exponent/modulo operation using his own retained key. According to another aspect, a k out of n secret sharing solution involves computing and storing a database having an entry for each unique combination of k keys that could be returned from among the n keys. After k keys have been received, the custodian looks up in the database the entry corresponding to the particular unique combination of secret owners who returned keys.
    Type: Grant
    Filed: May 11, 2001
    Date of Patent: January 23, 2007
    Assignee: Arcot Systems, Inc.
    Inventor: Sanguthevar Rajasekaran
  • Patent number: 7111789
    Abstract: Techniques are disclosed to increase the efficiency of multi-party authentication communications protocols. One technique includes a four party authentication method utilizing a general authenticator to store and provide a credit card authentication password and other payment information to an issuing bank and/or other parties involved in the transaction. Other techniques include the use of skeleton messages to minimize the forwarding of information through a forwarding party, the elimination of redundant communications exchanges, the use of a merchant appliance hardware solution to minimize system integration difficulties, and/or the imposition of credit card constraints. The techniques may be used singly or in combination.
    Type: Grant
    Filed: August 22, 2002
    Date of Patent: September 26, 2006
    Assignee: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, James Reno, Rammohan Varadarajan, Sanjay Vyas, Do-Pil Park, Robert Jerdonek
  • Patent number: 7020782
    Abstract: Searching is an important problem that arises in a variety of applications, particularly for computerized databases. Further, many such applications involve searching set of (possible very large) integers (e.g., credit card numbers, employee identifiers, customer identifiers, dates, parts numbers, etc.). We present techniques for integer searching in a computer database based on a improved form of hashing which we shall refer to as “size-dependent hashing.” This technique can be used to strike a balance between the available memory in the computer system and the required search time.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: March 28, 2006
    Assignee: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, James Reno
  • Publication number: 20050256890
    Abstract: The present invention describes techniques for performing searches in an efficient manner while minimizing the memory resources required to perform the searches. According to the techniques of the present invention, the number of comparisons needed to determine if a query element is in included in a set of elements is proportional to the length of the query element and independent of the number of elements in the set of elements.
    Type: Application
    Filed: July 25, 2005
    Publication date: November 17, 2005
    Applicant: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, Rajendra Gopalakrishna
  • Patent number: 6959303
    Abstract: The present invention describes techniques for performing searches in an efficient manner while minimizing the memory resources required to perform the searches. According to the techniques of the present invention, the number of comparisons needed to determine if a query element is in included in a set of elements is proportional to the length of the query element and independent of the number of elements in the set of elements.
    Type: Grant
    Filed: December 4, 2001
    Date of Patent: October 25, 2005
    Assignee: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, Rajendra A. Gopalakrishna
  • Patent number: 6928427
    Abstract: In an authorization system, access is defined by rules, roles and active rules. These definitions are preprocessed to form a bit array for each of a plurality of roles representing the rules that apply to that role. Once a bit array is calculated or generated for a given user based on that user's roles, the user bit array can be cached so that it need not be regenerated for each time the user requests access to resources. The rules used can either be role-based rules or active rules.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: August 9, 2005
    Assignee: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, Rajendra A. Gopalakrishna
  • Patent number: 6908030
    Abstract: An online transaction is effected between a user system, a merchant system and an issuer system. The user system generates a one-time number (OTN) to use as a card number for a transaction with the merchant. The user system generates the OTN as a function of various parameters and sends the OTN to the issuer and to the merchant. With the issuer communication, the user is first authenticated, so the issuer can associate the received OTN with the user even if the user's identity cannot be fully discerned from the OTN alone. In authenticating the user with the issuer, and possibly other authentications, the user sends the issuer a signed challenge where the challenge is a sequential challenge or a function of a prior challenge provided by the issuer. The issuer responds with an approval/denial message and, in the latter case, includes the next challenge to be used.
    Type: Grant
    Filed: October 31, 2001
    Date of Patent: June 21, 2005
    Assignee: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, Rammohan Varadarajan
  • Publication number: 20030172085
    Abstract: Searching is an important problem that arises in a variety of applications, particularly for computerized databases. Further, many such applications involve searching set of (possible very large) integers (e.g., credit card numbers, employee identifiers, customer identifiers, dates, parts numbers, etc.). We present techniques for integer searching in a computer database based on a improved form of hashing which we shall refer to as “size-dependent hashing.” This technique can be used to strike a balance between the available memory in the computer system and the required search time.
    Type: Application
    Filed: March 8, 2002
    Publication date: September 11, 2003
    Inventors: Sanguthevar Rajasekaran, James Reno
  • Publication number: 20030080183
    Abstract: An online transaction is effected between a user system, a merchant system and an issuer system. The user system generates a one-time number (OTN) to use as a card number for a transaction with the merchant. The user system generates the OTN as a function of various parameters and sends the OTN to the issuer and to the merchant. With the issuer communication, the user is first authenticated, so the issuer can associate the received OTN with the user even if the user's identity cannot be fully discerned from the OTN alone. In authenticating the user with the issuer, and possibly other authentications, the user sends the issuer a signed challenge where the challenge is a sequential challenge or a function of a prior challenge provided by the issuer. The issuer responds with an approval/denial message and, in the latter case, includes the next challenge to be used.
    Type: Application
    Filed: October 31, 2001
    Publication date: May 1, 2003
    Inventors: Sanguthevar Rajasekaran, Rammohan Varadarajan
  • Publication number: 20030042301
    Abstract: Techniques are disclosed to increase the efficiency of multi-party authentication communications protocols. One technique includes a four party authentication method utilizing a general authenticator to store and provide a credit card authentication password and other payment information to an issuing bank and/or other parties involved in the transaction. Other techniques include the use of skeleton messages to minimize the forwarding of information through a forwarding party, the elimination of redundant communications exchanges, the use of a merchant appliance hardware solution to minimize system integration difficulties, and/or the imposition of credit card constraints. The techniques may be used singly or in combination.
    Type: Application
    Filed: August 22, 2002
    Publication date: March 6, 2003
    Inventors: Sanguthevar Rajasekaran, James Reno, Rammohan Varadarajan, Sanjay Vyas, Do-Pil Park, Robert Jerdonek
  • Publication number: 20020174355
    Abstract: Techniques for efficiently searching encrypted searchable spaces. For example, embodiments of the present invention provide techniques for searching a plurality of files that are stored in encrypted (or ciphertext) form. According to embodiments of the present invention, the search can usually be performed by decrypting only a portion of the encrypted searchable space. According to an embodiment of the present invention, the search techniques determine a set of files comprising one or more files from the plurality of encrypted files that contain a user-specified query element. The set of files is usually determined by decrypting only a subset of the plurality of encrypted files.
    Type: Application
    Filed: March 11, 2002
    Publication date: November 21, 2002
    Applicant: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, Rammohan Varadarajan
  • Publication number: 20020164033
    Abstract: An n person secret sharing solution computes n unique keys to be distributed to the secret owners along with an exponentiated version of the secret. The custodian performs an exponent/modulo operation each time one of the keys is received from one of the secret owners. Alternatively, n+1 keys are created by the custodian, and the custodian retains one key after distributing the remaining n keys to the secret owners. After the custodian has received and processed the n keys from the secret owners, he performs an exponent/modulo operation using his own retained key. According to another aspect, a k out of n secret sharing solution involves computing and storing a database having an entry for each unique combination of k keys that could be returned from among the n keys. After k keys have been received, the custodian looks up in the database the entry corresponding to the particular unique combination of secret owners who returned keys.
    Type: Application
    Filed: May 11, 2001
    Publication date: November 7, 2002
    Inventor: Sanguthevar Rajasekaran
  • Publication number: 20020143766
    Abstract: In an authorization system, access is defined by rules, roles and active rules. These definitions are preprocessed to form a bit array for each of a plurality of roles representing the rules that apply to that role. Once a bit array is calculated or generated for a given user based on that user's roles, the user bit array can be cached so that it need not be regenerated for each time the user requests access to resources. The rules used can either be role-based rules or active rules.
    Type: Application
    Filed: March 8, 2002
    Publication date: October 3, 2002
    Applicant: Arcot Systems, Inc.
    Inventors: Sanguthevar Rajasekaran, Rajendra A. Gopalakrishna
  • Publication number: 20020124003
    Abstract: The present invention describes techniques for performing searches in an efficient manner while minimizing the memory resources required to perform the searches. According to the techniques of the present invention, the number of comparisons needed to determine if a query element is in included in a set of elements is proportional to the length of the query element and independent of the number of elements in the set of elements.
    Type: Application
    Filed: December 4, 2001
    Publication date: September 5, 2002
    Inventors: Sanguthevar Rajasekaran, Rajendra A. Gopalakrishna