Patents by Inventor Shashank Agrawal

Shashank Agrawal 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: 20220309496
    Abstract: A method includes a validation computer receiving an authorization request message comprising a user state and a user proof from a user device. The user state comprises first and second user state elements. The user proof comprises first, second, and third user proof elements. The validation computer computes a first verification value by multiplying the first user proof element raised to the power of the second user state element, and the second user proof element raised to the power of the first user state element. The computer computes a second verification value by raising the second user proof element to the power of the second user state element. The computer compares the first verification value to a first accumulated state element of an accumulated state. The compares the second verification value to a second accumulated state element. The validation computer authorizes the authorization request message based on the comparison steps.
    Type: Application
    Filed: September 25, 2020
    Publication date: September 29, 2022
    Inventors: Shashank Agrawal, Srinivasan Raghuraman
  • Publication number: 20220286290
    Abstract: Techniques of authenticating a first device of a user to a second device are disclosed. The method enables the second device to perform authentication using a biometric template stored on the first device and a biometric measurement. Homomorphic encryption may be used by the first device to encrypt the biometric template and the second device to determine an encrypted similarity metric between the biometric template and the biometric measurement. The second device can also determine an encrypted code using an authentication function and the encrypted similarity metric. The second device sends the encrypted code and the encrypted similarity metric to be decrypted by the first device. The second device can receive a response from the first device, indicating whether a decrypted similarity metric exceeds a threshold; and whether the decrypted code matches a test code. The second device can then authenticate the user based on the response.
    Type: Application
    Filed: May 25, 2022
    Publication date: September 8, 2022
    Inventors: Payman Mohassel, Shashank Agrawal, Pratyay Mukherjee, Saikrishna Badrinarayanan
  • Patent number: 11438152
    Abstract: Systems and methods for improved distributed symmetric cryptography are disclosed. A client computer may communicate with a number of cryptographic devices in order to encrypt or decrypt data. Each cryptographic device may possess a secret share and a verification share, which may be used in the process of encrypting or decrypting data. The client computer may generate a commitment and transmit the commitment to the cryptographic devices. Each cryptographic device may generate a partial computation based on the commitment and their respective secret share, and likewise generate a partial signature based on the commitment and their respective verification share. The partial computations and partial signatures may be transmitted to the client computer. The client computer may use the partial computations and partial signatures to generate a cryptographic key and verification signature respectively. The client computer may use the cryptographic key to encrypt or decrypt a message.
    Type: Grant
    Filed: January 31, 2020
    Date of Patent: September 6, 2022
    Assignee: VISA INTERNATIONAL SERVICE ASSOCIATION
    Inventors: Pratyay Mukherjee, Shashank Agrawal, Peter Rindal, Atul Luykx, Wei Dai
  • Patent number: 11411738
    Abstract: Systems, methods, and apparatuses of using biometric information to authenticate a first device of a user to a second device are described herein. A method includes storing, by the first device, a first key share of a private key and a first template share of a biometric template of the user. The second device stores a public key, and one or more other devices of the user store other key shares and other template shares. The first device receives a challenge message from the second device, measures biometric features of the user to obtain a measurement vector, and sends the measurement vector and the challenge message to the other devices. The first device receives partial computations, generated using a respective template share, key share, and the challenge message, from the other devices, uses them to generate a signature of the challenge message and send the signature to the second device.
    Type: Grant
    Filed: October 4, 2019
    Date of Patent: August 9, 2022
    Assignee: VISA INTERNATIONAL SERVICE ASSOCIATION
    Inventors: Shashank Agrawal, Saikrishna Badrinarayanan, Payman Mohassel, Pratyay Mukherjee
  • Publication number: 20220207086
    Abstract: Various embodiments of the present invention provide methods, apparatuses, systems, computing devices, and/or the like that are configured to enable effective and efficient aggregate user-document interaction monitoring in collaborative document server systems. For example, certain embodiments of the present invention provide methods, apparatuses, systems, computing devices, and/or the like that are configured to perform aggregate user-document interaction monitoring in collaborative document server systems using one or more of collaborative document graph-based user interfaces, collaborative document graph-based interface objects, edge-wise visual effect objects, collaborative document node objects, collaborative document node elements, document transition edge objects, and document transition edge elements.
    Type: Application
    Filed: December 28, 2020
    Publication date: June 30, 2022
    Inventors: Shashank Prasad RAO, Bharat AGARWAL, Avinash AGRAWAL, Viraj SINHA
  • Patent number: 11368308
    Abstract: Techniques of authenticating a first device of a user to a second device are disclosed. The method enables the second device to perform authentication using a biometric template stored on the first device and a biometric measurement. Homomorphic encryption may be used by the first device to encrypt the biometric template and the second device to determine an encrypted similarity metric between the biometric template and the biometric measurement. The second device can also determine an encrypted code using an authentication function and the encrypted similarity metric. The second device sends the encrypted code and the encrypted similarity metric to be decrypted by the first device. The second device can receive a response from the first device, indicating whether a decrypted similarity metric exceeds a threshold; and whether the decrypted code matches a test code. The second device can then authenticate the user based on the response.
    Type: Grant
    Filed: January 9, 2020
    Date of Patent: June 21, 2022
    Assignee: Visa International Service Association
    Inventors: Payman Mohassel, Shashank Agrawal, Pratyay Mukherjee, Saikrishna Badrinarayanan
  • Publication number: 20220129884
    Abstract: Blockchain-based, smart contract platforms have great promise to remove trust and add transparency to distributed applications. However, this benefit often comes at the cost of greatly reduced privacy. Techniques for implementing a privacy-preserving smart contract is described. The system can keep accounts private while not losing functionality and with only a limited performance overhead. This is achieved by building a confidential and anonymous token on top of a cryptocurrency. Multiple complex applications can also be built using the smart contract system.
    Type: Application
    Filed: January 7, 2022
    Publication date: April 28, 2022
    Inventors: Shashank Agrawal, Karl Benedikt Bünz, Mahdi Zamani, Dan Boneh
  • Patent number: 11257077
    Abstract: Blockchain-based, smart contract platforms have great promise to remove trust and add transparency to distributed applications. However, this benefit often comes at the cost of greatly reduced privacy. Techniques for implementing a privacy-preserving smart contract is described. The system can keep accounts private while not losing functionality and with only a limited performance overhead. This is achieved by building a confidential and anonymous token on top of a cryptocurrency. Multiple complex applications can also be built using the smart contract system.
    Type: Grant
    Filed: November 30, 2018
    Date of Patent: February 22, 2022
    Assignees: Visa International Service Association, The Board of Trustees of the Leland Stanford Junior University
    Inventors: Shashank Agrawal, Karl Benedikt Bünz, Mahdi Zamani, Dan Boneh
  • Publication number: 20220021537
    Abstract: Methods and systems for privacy-preserving identity attribute verification are presented. During an interaction between a relying entity and a user, a relying entity computer can transmit a policy token to a user device. The policy token may indicate the information needed by the relying entity in order to perform the interaction. The user device can verify the policy token, then use the policy token in conjunction with an identity token to generate a zero-knowledge proof. The user device may transmit the zero-knowledge proof to an identity service provider computer. The identity service provider computer may verify the zero-knowledge proof, then generate a verification message. The identity service provider computer may sign the verification message and transmit the signed verification message to the relying entity computer. The relying entity computer may verify the verification message and complete the interaction with the user.
    Type: Application
    Filed: July 14, 2020
    Publication date: January 20, 2022
    Inventors: Kim Ritter Wagner, Sunpreet Singh Arora, Gaven James Watson, Mihai Christodorescu, Shashank Agrawal
  • Publication number: 20210409405
    Abstract: An initiator device can broadcast a witness request to one or more authentication devices. The one or more authentication devices can then determine an assurance level from a range of assurance levels and determine a token share corresponding to the assurance level. The initiator device can then receive, from the one or more authentication devices, at least one witness response comprising the token share corresponding to the assurance level. The initiator device can generate an authentication token using a set of token shares. The initiator device can then transmit the authentication token to an authentication server, wherein the authentication server verifies the authentication token.
    Type: Application
    Filed: August 30, 2019
    Publication date: December 30, 2021
    Inventors: Mastooreh Salajegheh, Shashank Agrawal, Eric Le Saint, Payman Mohassel, Mihai Christodorescu
  • Publication number: 20210336792
    Abstract: Systems, methods, and apparatuses of using biometric information to authenticate a first device of a user to a second device are described herein. A method includes storing, by the first device, a first key share of a private key and a first template share of a biometric template of the user. The second device stores a public key, and one or more other devices of the user store other key shares and other template shares. The first device receives a challenge message from the second device, measures biometric features of the user to obtain a measurement vector, and sends the measurement vector and the challenge message to the other devices. The first device receives partial computations, generated using a respective template share, key share, and the challenge message, from the other devices, uses them to generate a signature of the challenge message and send the signature to the second device.
    Type: Application
    Filed: October 4, 2019
    Publication date: October 28, 2021
    Inventors: Shashank Agrawal, Saikrishna Badrinarayanan, Payman Mohassel, Pratyay Mukherjee
  • Publication number: 20210243020
    Abstract: Systems and methods for improved distributed symmetric cryptography are disclosed. A client computer may communicate with a number of cryptographic devices in order to encrypt or decrypt data. Each cryptographic device may possess a secret share and a verification share, which may be used in the process of encrypting or decrypting data. The client computer may generate a commitment and transmit the commitment to the cryptographic devices. Each cryptographic device may generate a partial computation based on the commitment and their respective secret share, and likewise generate a partial signature based on the commitment and their respective verification share. The partial computations and partial signatures may be transmitted to the client computer. The client computer may use the partial computations and partial signatures to generate a cryptographic key and verification signature respectively. The client computer may use the cryptographic key to encrypt or decrypt a message.
    Type: Application
    Filed: January 31, 2020
    Publication date: August 5, 2021
    Inventors: Pratyay Mukherjee, Shashank Agrawal, Peter Rindal, Atul Luykx, Wei Dai
  • Publication number: 20210243026
    Abstract: Embodiments disclosed herein are directed to methods and systems of password-based threshold authentication, which distributes the role of an authentication server among multiple servers. Any t servers can collectively verify passwords and generate authentication tokens, while no t?1 servers can forge a valid token or mount offline dictionary attacks.
    Type: Application
    Filed: October 15, 2018
    Publication date: August 5, 2021
    Inventors: Payman Mohassel, Shashank Agrawal, Pratyay Mukherjee, Peihan Miao
  • Publication number: 20210075781
    Abstract: At an authorization server, a shared secret electronic key may be shared with a second computer. A selection to use a system to complete a transaction may be received from a first computing device. An image may be communicated to the first computing device. A digital representation entered by the user representing the image and a PIN based on the copy of the shared electronic key may be received from the second computing device. The system and method may determine if the digital representation entered by the user on the second computing device matches the image communicated to the first computing device. The system and method may determine if the PIN based on the copy of the shared electronic key from the second computing device is as expected. In response to determining the digital representation entered by the user matches the image and the PIN the second computing device is as expected, the user may be authorized.
    Type: Application
    Filed: September 11, 2019
    Publication date: March 11, 2021
    Inventors: Maliheh Shirvanian, Shashank Agrawal
  • Publication number: 20200279258
    Abstract: Systems, methods, and computer readable media are provided for improving the usability of a cryptogram generated in a first cryptographic protocol such as triple-DES. The methods may generate a first cryptogram using a first identifier in a first cryptographic protocol, stored in a key store within an insecure memory of the mobile communication device, generate, within a secure memory of the mobile communication device, a second cryptogram using a second identifier in a second cryptographic protocol, stored in the secure memory, combining, the first cryptogram and a number of characters of the second cryptogram equal to the length of the first cryptogram to generate a third cryptogram and transmitting the third cryptogram to an payment processing network to validate a transaction. A transaction associated with the third cryptogram may be validated by an authorization entity or an issue entity.
    Type: Application
    Filed: September 26, 2019
    Publication date: September 3, 2020
    Inventors: Shashank Agrawal, Dmitri Bannikov, Atul Luykx, Payman Mohassel, Sergey Smirnoff, Selvaganesh Vasudevan, Gaven Watson
  • Publication number: 20200259651
    Abstract: Systems and methods for threshold authenticated encryption are provided. A collection of cryptographic devices may encrypt or decrypt a message, provided that a threshold number of those devices participate in the encryption process. One cryptographic device may generate a commitment message and transmit it to the other selected devices. Those devices may each perform a partial computation using the commitment message, and transmit the partial computations back to the encrypting or decrypting device. The encrypting or decrypting device may use those partial computations to produce a cryptographic key, which may then be used to encrypt or decrypt the message.
    Type: Application
    Filed: October 30, 2017
    Publication date: August 13, 2020
    Inventors: Payman Mohassel, Pratyay Mukherjee, Shashank Agrawal, Eric Le Saint
  • Publication number: 20200228341
    Abstract: Techniques of authenticating a first device of a user to a second device are disclosed. The method enables the second device to perform authentication using a biometric template stored on the first device and a biometric measurement. Homomorphic encryption may be used by the first device to encrypt the biometric template and the second device to determine an encrypted similarity metric between the biometric template and the biometric measurement. The second device can also determine an encrypted code using an authentication function and the encrypted similarity metric. The second device sends the encrypted code and the encrypted similarity metric to be decrypted by the first device. The second device can receive a response from the first device, indicating whether a decrypted similarity metric exceeds a threshold; and whether the decrypted code matches a test code. The second device can then authenticate the user based on the response.
    Type: Application
    Filed: January 9, 2020
    Publication date: July 16, 2020
    Inventors: Payman Mohassel, Shashank Agrawal, Pratyay Mukherjee, Saikrishna Badrinarayanan
  • Publication number: 20200219099
    Abstract: Disclosed is a system, method, and computer program product for determining solvency of a digital asset exchange system. The method includes identifying a plurality of blockchain addresses corresponding to a plurality of users of the digital asset exchange system, generating a first commitment to an amount of digital assets corresponding to the plurality of blockchain addresses, generating a second commitment to a balance of each user of the plurality of users, generating a first component of a zero-knowledge algorithm configured to receive, as input, the first commitment, and to output a value generated based on each public key, generating a second component of the zero-knowledge algorithm configured to receive, as input, the second commitment, and to output a value generated based on each user balance, and determining, with at least one processor, that the digital asset exchange system is solvent based on the zero-knowledge algorithm.
    Type: Application
    Filed: July 2, 2018
    Publication date: July 9, 2020
    Inventors: Payman Mohassel, Shashank Agrawal, Chaya Ganesh
  • Publication number: 20190164153
    Abstract: Blockchain-based, smart contract platforms have great promise to remove trust and add transparency to distributed applications. However, this benefit often comes at the cost of greatly reduced privacy. Techniques for implementing a privacy-preserving smart contract is described. The system can keep accounts private while not losing functionality and with only a limited performance overhead. This is achieved by building a confidential and anonymous token on top of a cryptocurrency. Multiple complex applications can also be built using the smart contract system.
    Type: Application
    Filed: November 30, 2018
    Publication date: May 30, 2019
    Inventors: Shashank Agrawal, Karl Benedikt Bünz, Mahdi Zamani, Dan Boneh