Abstract: Conducting secure transfers between computing devices can pose a challenge. Therefore, an oblivious transfer can be used to conduct a secure transfer. The oblivious transfer (OT) is an interactive protocol between two parties: a sender computing device and a receiver computing device. An OT protocol involves the sender computing device holding two messages m0 and m1, and the receiver computing device holding a bit b? {0, 1}. At the end of the protocol, the receiver computing device should only learn the message mb and nothing about the other message m1?b, while the sender computing device should learn nothing about the bit b. With the steady progress in quantum computing, several post-quantum oblivious transfer protocols can be derived.

Abstract: Embodiments are directed to methods and systems for crypto-agile encryption and decryption. A computer system can possess a protocol file that identifies one or more cryptographic software modules. Using these cryptographic software modules, the computer system can generate a plurality of shared secrets and a session key, then use the session key to encrypt a message. The message can be sent to a server computer that can subsequently decrypt the message. At a later time, the protocol file can be updated to identify a different set of cryptographic software modules, which can be used to encrypt messages. Further, the server computer can transmit additional cryptographic software modules to the computer system, enabling the computer system to use those cryptographic software modules to generate cryptographic keys. As such, the cryptographic protocol file can be changed in response to changes in the cryptographic needs of the computer system.

Abstract: Embodiments are directed to methods and systems for crypto-agile encryption and decryption. A computer system can possess a protocol file that identifies one or more cryptographic software modules. Using these cryptographic software modules, the computer system can generate a plurality of shared secrets and a session key, then use the session key to encrypt a message. The message can be sent to a server computer that can subsequently decrypt the message. At a later time, the protocol file can be updated to identify a different set of cryptographic software modules, which can be used to encrypt messages. Further, the server computer can transmit additional cryptographic software modules to the computer system, enabling the computer system to use those cryptographic software modules to generate cryptographic keys. As such, the cryptographic protocol file can be changed in response to changes in the cryptographic needs of the computer system.

Abstract: Conducting secure transfers between computing devices can pose a challenge. Therefore, an oblivious transfer can be used to conduct a secure transfer. The oblivious transfer (OT) is an interactive protocol between two parties: a sender computing device and a receiver computing device. An OT protocol involves the sender computing device holding two messages m0 and m1, and the receiver computing device holding a bit b? {0, 1}. At the end of the protocol, the receiver computing device should only learn the message mb and nothing about the other message m1?b, while the sender computing device should learn nothing about the bit b. With the steady progress in quantum computing, several post-quantum oblivious transfer protocols can be derived.

Abstract: Improvements to post-quantum lattice-based digital signature schemes are disclosed. By sampling cryptographic material, including cryptographic key matrices and masking vectors from a uniform distribution, embodiments eliminate the need for a security check during generation of a digital signature vector. As a result, digital signatures can be generated faster and at a lower failure rate. A generating device can generate a verification matrix A and a secret matrix S from a uniform distribution, and an error matrix E from a special distribution (such as a Gaussian). The generating device can combine the three matrices to generate a public matrix Y. The first and the fourth matrices (A, Y) can be used as a public key used to verify digital signatures. The second and the third matrices (S, E) can be used as a private key used to generate digital signatures.

Abstract: Embodiments can perform efficient OT (oblivious transfer) protocols to efficiently establish OT correlations that could be used for an MPC protocol. The present embodiments relate to a non-interactive OT (NIOT) protocol using a key encapsulation mechanism (KEM). Two OT protocols are non-interactive OTs, in which a sender generates private, public key pair (pk, sk) that is independent of its input or generated OT correlations. The two OT protocols use a cryptographic hash function and a one-way secure dense key encapsulation mechanism (KEM).

Abstract: Embodiments are directed to methods and systems for crypto-agile encryption and decryption. A computer system can possess a protocol file that identifies one or more cryptographic software modules. Using these cryptographic software modules, the computer system can generate a plurality of shared secrets and a session key, then use the session key to encrypt a message. The message can be sent to a server computer that can subsequently decrypt the message. At a later time, the protocol file can be updated to identify a different set of cryptographic software modules, which can be used to encrypt messages. Further, the server computer can transmit additional cryptographic software modules to the computer system, enabling the computer system to use those cryptographic software modules to generate cryptographic keys. As such, the cryptographic protocol file can be changed in response to changes in the cryptographic needs of the computer system.

Abstract: Improvements to post-quantum lattice-based digital signature schemes are disclosed. By sampling cryptographic material, including cryptographic key matrices and masking vectors from a uniform distribution, embodiments eliminate the need for a security check during generation of a digital signature vector. As a result, digital signatures can be generated faster and at a lower failure rate. A generating device can generate a verification matrix A and a secret matrix S from a uniform distribution, and an error matrix E from a special distribution (such as a Gaussian). The generating device can combine the three matrices to generate a public matrix Y. The first and the fourth matrices (A, Y) can be used as a public key used to verify digital signatures. The second and the third matrices (S, E) can be used as a private key used to generate digital signatures.

Abstract: Improvements to post-quantum lattice-based digital signature schemes are disclosed. By sampling cryptographic material, including cryptographic key matrices and masking vectors from a uniform distribution, embodiments eliminate the need for a security check during generation of a digital signature vector. As a result, digital signatures can be generated faster and at a lower failure rate. A generating device can generate a verification matrix A and a secret matrix S from a uniform distribution, and an error matrix E from a special distribution (such as a Gaussian). The generating device can combine the three matrices to generate a public matrix Y. The first and the fourth matrices (A, Y) can be used as a public key used to verify digital signatures. The second and the third matrices (S, E) can be used as a private key used to generate digital signatures.

Abstract: Improvements to post-quantum lattice-based digital signature schemes are disclosed. By sampling cryptographic material, including cryptographic key matrices and masking vectors from a uniform distribution, embodiments eliminate the need for a security check during generation of a digital signature vector. As a result, digital signatures can be generated faster and at a lower failure rate. A generating device can generate a verification matrix A and a secret matrix S from a uniform distribution, and an error matrix E from a special distribution (such as a Gaussian). The generating device can combine the three matrices to generate a public matrix Y. The first and the fourth matrices (A, Y) can be used as a public key used to verify digital signatures. The second and the third matrices (S, E) can be used as a private key used to generate digital signatures.

Abstract: Blinding techniques can be used to obfuscate or otherwise modify a quantum-secure public key (and the corresponding private, or secret, key) such as a lattice-based public key. Blinding of a public key can include selecting a blinding parameter, which can be a vector or matrix, and applying the blinding parameter to the public key. A corresponding modification can be applied to the private key such that data encrypted using the blinded public key can be decrypted using the blinded public key. When a device needs to send a public key in the clear, e.g., in the course of establishing a secure communication session, the device can generate a blinded public key from its static public key and send the blinded key instead of the static public key.