At a transmitter node, a commitment value C is obtained as a function of a message m. The commitment value C and transmitter terms of use T.sup.A for the message m are then sent to a receiver node without disclosing the message m. A cryptographic receiver signature S.sub.B over the commitment value C and the transmitter terms of use T.sup.A is received from the receiver node, where the cryptographic receiver signature S.sub.B is signed with a private key kprv-B associated with the receiver node. The receiver signature S.sub.B may be authenticated using a public key kpuh-B for the receiver node. If the receiver signature S.sub.B is successfully authenticated, the message m and the receiver signature S.sub.B are signed using a private key kprv-A for the transmitter node to obtain a transmitter signature S.sub.A. The message m and the transmitter signature S.sub.A may then be sent to the receiver node.

The techniques described herein may provide an efficient and secure two-party distributed signing protocol, for example, for the IEEE P1363 standard. For example, in an embodiment, method may comprise generating, at a key generation center, a first partial private cryptographic key for a user ID and a second partial private cryptographic key for the user ID, transmitting the first partial private cryptographic key to a first other device, transmitting the second partial private cryptographic key to a second other device, and generating a distributed cryptographic signature for a message using the first partial private cryptographic key and the second partial private cryptographic key.

Systems and methods that provide improved security and scalability in digital token exchange are disclosed. In one example, a system may receive from a requester one or more old cryptographically signed tokens each including a shared class and denomination. After validating the previously issued Value Tokens, the system may sign newly issued Value Tokens having the shared class and send them to the requester as a swap for the previously issued Value Tokens. Some tokens have intrinsic value while other coded Value Tokens require reference to a record of valid tokens to validate them. The system allows tokens of one type to be swapped for tokens of the other type, but issues intrinsic Value Tokens only as a swap for coded Value Tokens.

A system for providing access is configured to receive an application access request from an application for authorization to access and a sensitive data access request from the application for authorization to access a document that includes sensitive data. The system is further configured to determine to authorize access to the application in response to the application access request; to determine the user authentication device in response to the sensitive data access request; to provide a secondary request for authorization to access sensitive data to the user authentication device in response to the sensitive data access request, receive a secondary request response from the user authentication device to the secondary request; and to provide the secondary request response to the application enabling access to the sensitive data, where the document is encrypted for delivery to the application for the user using a blinding secret and an identity private key.

Methods, systems, and computer media provide attestation tokens that protect the integrity of communications transmitted from client devices, while at the same time avoiding the use of stable device identifiers that could be used to track client devices or their users. In one approach, client devices can receive batches of N device integrity elements from a device integrity computing system, each corresponding to a different public key. The N device elements can be signed by a device integrity computing system. The signing by the device integrity computing system can be signing with a blind signature scheme. Client devices can include throttlers imposing limits on the quantity of attestation tokens created by the client device.

Methods, systems, and apparatus, including a method for determining network measurements. In some aspects, a method includes receiving, by a first aggregation server and from each of multiple client devices, encrypted impression data. A second aggregation server received from each of at least a portion of the multiple client devices, conversion data that includes, for each conversion recorded by the client device, encrypted conversion value data. The first aggregation server and the second aggregation server perform a multi-party computation process to decrypt the encrypted impression data and the encrypted conversion data.

Methods, systems, and apparatus, including a method for determining network measurements. In some aspects, a method includes receiving, by a first aggregation server and from each of multiple client devices, encrypted impression data. A second aggregation server receives, from each of at least a portion of the multiple client devices, encrypted conversion data. The first aggregation server and the second aggregation server perform a multi-party computation process to decrypt the encrypted impression data and the encrypted conversion data. Each portion of decrypted impression data and each portion of decrypted conversion data is sent to a respective reporting system.

The application provides a data encryption and decryption method, device, storage medium, and encrypted file, and relates to the technical field of data processing. The method for data encryption includes: obtaining a first key, and performing an obfuscation operation on the first key and data to be encrypted to obtain obfuscation operation result data; obtaining a second key, and obtaining a first signature of the obfuscation operation result data according to the second key; obtaining a third key, and encrypting the first key, the data to be encrypted and the first signature using the third key to obtain a target ciphertext; obtaining a fourth key, and obtaining a second signature of the target ciphertext according to the fourth key; generating an encrypted file including the target ciphertext and the second signature. With the technical solutions of the application, security of data protection can be improved.

A biometric scanner apparatus comprising a biometric sensor configured to scan at least a biological sample and receive a unique biometric pattern, a secret data extractor configured to receive the unique biometric pattern from the biometric sensor and generate an output comprising a sample-specific secret, and a sample identifier circuit communicatively connected to the secret data extractor wherein the sample identifier circuit is configured to produce at least an output comprising a secure proof of the sample-specific secret.

Signature-based authentication is a core cryptographic primitive essential for most secure networking protocols. A new signature scheme, MSS, allows a client to efficiently authenticate herself to a server. The new scheme is modeled in an offline/online model where client online time is premium. The offline component derives basis signatures that are then composed based on the data being signed to provide signatures efficiently and securely during run-time. MSS requires the server to maintain state and is suitable for applications where a device has long-term associations with the server. MSS allows direct comparison to hash chains-based authentication schemes used in similar settings, and is relevant to resource-constrained devices, e.g., IoT. MSS instantiations are derived for two cryptographic families, assuming the hardness of RSA and decisional Diffie-Hellman (DDH) respectively. Then used is the new scheme to design an efficient time-based one-time password (TOTP) protocol.