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.

Abstract: Systems and methods for adaptive attack resistant 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 multiple secret shares corresponding to distinct secret values, which may be used in the process of encrypting or decrypting data. The client computer may generate multiple commitments and transmit those commitments to the cryptographic devices. Each cryptographic device may generate a partial computation based on the commitments and their respective secret shares. The partial computations may be transmitted to the client computer. The client computer may use the partial computations to generate a cryptographic key. The client computer may use the cryptographic key to encrypt a message or decrypt ciphertext.

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.

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.

Abstract: Methods and systems for gateway agnostic tokenization are disclosed. Gateway agnostic tokenization enables a resource provider to quickly, safely, and efficiently route a token for authorization via any appropriate gateway computer. As part of an interaction with a user, a resource provider can transmit a token to an edge computer. The edge computer can then forward the token to a gateway computer. The gateway computer can identify a data item comprising two ciphertexts associated with the token. The edge computer and gateway computer can collectively decrypt the two ciphertexts to obtain a credential. The gateway computer can then forward the credential to an authorizing entity computer. The authorizing entity computer can then determine whether or not to authorize the interaction.

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.

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.

Abstract: Systems and methods for adaptive attack resistant 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 multiple secret shares corresponding to distinct secret values, which may be used in the process of encrypting or decrypting data. The client computer may generate multiple commitments and transmit those commitments to the cryptographic devices. Each cryptographic device may generate a partial computation based on the commitments and their respective secret shares. The partial computations may be transmitted to the client computer. The client computer may use the partial computations to generate a cryptographic key. The client computer may use the cryptographic key to encrypt a message or decrypt ciphertext.

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.

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.

Abstract: Secure protocols for external-facing authentication are provided for both user templates stored on their devices and the biometric measurement captured by external sensors of an access device. The protocols provide different levels of security, ranging from passive security with some leakage to active security with no leakage. A packing technique is also provided. Zero-knowledge techniques are used during enrollment to validate a norm of user templates and knowledge of the plaintext biometric template. One enrolled, the verifier can sign the encrypted template for use in a later matching phase with an access device.

Abstract: Systems, methods, and apparatuses for protecting a secret on a device with limited memory, while still providing tamper resistance, are described. To achieve security, an encoding computer can apply a memory-hard function MHF to a secret S and determine a result Y, then determine a proof ? for the result Y. Then, the encoding computer can send a codeword C comprising the secret S and the proof ? to a decoding computer. The decoding computer can retrieve the codeword C from persistent memory and parse the secret S and the proof ?. The decoding device can use transient memory to decode the codeword C by verifying the proof ? was generated with the secret S and the result Y. When the correctness of the result Y is verified, the decoding device can apply a cryptographic function to input data using the secret S then reset the transient memory.

Abstract: A method, system, and computer program product generate, with a payment network, a first value (a) and a second value (ga), the second value (ga) based on the first value (a) and a generator value (g); generate, with the payment network, a plurality of random merchant numbers (mi) for a respective plurality of merchant banks; determine, with the payment network, a merchant product (M) based on a product of the plurality of random merchant numbers (mi); generate, with the payment network, a public key (pki) based on the second value (ga), the merchant product (M), and the random merchant number (mi) and a random key (rki) based on the merchant product (M) and the random merchant number (mi) for each respective merchant bank; and communicate, with the payment network, the public key (pki) and the random key (rki) to at least one respective merchant bank.

Abstract: Techniques of generating a lattice-based verification matrix and signature vector are disclosed. The method enables generating device to sample a gadget matrix and then generate a reduced gadget matrix. The generating device may then sample a trapdoor matrix and use the trapdoor matrix and the reduced gadget matrix to generate a verification matrix. A sending device may receive the trapdoor matrix and the verification matrix from the generating device, in addition to receiving a message. The sending device may then use the trapdoor matrix and the verification matrix to generate a signature vector for the message. A verification device can receive the verification matrix, the message, and the signature vector. The verification device may use the verification matrix and the signature vector to verify the message.

Abstract: Systems, methods, and apparatuses for protecting a secret on a device with limited memory, while still providing tamper resistance, are described. To achieve security, an encoding computer can apply a memory-hard function MHF to a secret S and determine a result Y, then determine a proof ? for the result Y. Then, the encoding computer can send a codeword C comprising the secret S and the proof ? to a decoding computer. The decoding computer can retrieve the codeword C from persistent memory and parse the secret S and the proof ?. The decoding device can use transient memory decode the codeword C by verifying the proof ? was generated with the secret S and the result Y. When the correctness of the result Y is verified, the decoding device can apply a cryptographic function to input data using the secret S then reset the transient memory.

Abstract: Several round-efficient solitary multi-party computation protocols with guaranteed output delivery are disclosed. A plurality of input devices and an output device can collectively perform a computation using methods such as fully homomorphic encryption. The output of the computation is only known to the output device. Some number of these devices may be corrupt. However, even in the presence of corrupt devices, the output device can still either generate a correct output or identify that the computation was compromised. These protocols operate under different assumptions regarding the communication infrastructure (e.g., broadcast vs point-to-point), the number of participating devices, and the number of corrupt devices. These protocols are round-efficient in that they require a minimal number of communication rounds to calculate the result of the multi-party computation.

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.

Abstract: Systems and methods for adaptive attack resistant 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 multiple secret shares corresponding to distinct secret values, which may be used in the process of encrypting or decrypting data. The client computer may generate multiple commitments and transmit those commitments to the cryptographic devices. Each cryptographic device may generate a partial computation based on the commitments and their respective secret shares. The partial computations may be transmitted to the client computer. The client computer may use the partial computations to generate a cryptographic key. The client computer may use the cryptographic key to encrypt a message or decrypt ciphertext.

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.

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.