Abstract: Techniques are disclosed relating to functional encryption schemes for attribute-weighted sum (AWS) functionality that support the uniform model of computation. In some embodiments, a device is configured for encrypting for a functional encryption scheme in the public key setting supporting multiple secret keys and multiple ciphertexts. In some embodiments the disclosed techniques may support both public and private attributes of arbitrary lengths.

Abstract: A method and system for verifying distributed computations across multiple untrusted computing nodes. A setup entity generates cryptographic reference strings including succinct non-interactive arguments (SNARGs) and batch arguments (seBARGs) for multiple proof hierarchy levels. Prover entities compute state transitions using nondeterministic inputs, generate proofs for individual computation steps, and merge proofs hierarchically to create compact proofs whose size grows logarithmically with computation length rather than linearly. A verifier entity validates the merged proofs at each level. In a zero-knowledge variant, the setup entity additionally generates encryption keys and zero-knowledge proof parameters. Prover entities encrypt all computation states and wrap proofs in zero-knowledge layers, hiding sensitive intermediate values and witnesses while maintaining verifiability.

Abstract: The present disclosure provides a method for randomized multi-input functional encryption. A setup processor generates, for each input, a component for generating a proof, public-private key pairs, an obfuscated program for verifying ciphertexts and outputting a proof, and an encryption key. The setup processor generates a master secret key and transmits encryption keys to an encryption processor and the master secret key to a key generation processor. The encryption processor computes ciphertexts, generates proofs, and produces final ciphertexts. The key generation processor receives the master secret key and a randomized function, samples a PRF key, generates an obfuscated program, and transmits a function key to a decryption processor. The decryption processor receives the function key and ciphertexts, calculates a decryption result, and electronically stores the result.

Abstract: The invention relates to systems, methods, network devices, and machine-readable media for encrypting and decrypting messages in a decentralized multi-authority attribute-based encryption (MA-ABE) scheme that is provably fully-adaptively secure, specifically, secure against an attacker that may corrupt some of the authorities as well as perform key queries adaptively throughout the lifetime of the system.

Abstract: The present disclosure provides a method and system for implementing a streaming functional encryption scheme with adaptive security. The method includes building a single-key, single-ciphertext, adaptively secure streaming functional encryption scheme and executing a bootstrap of this scheme into a full multi-key, multi-ciphertext, public-key adaptive streaming functional encryption scheme. The method further includes implementing setup, encryption, key generation, and decryption routines for both the single-key scheme and the bootstrapped scheme. The system comprises a processor and a memory storing instructions to execute these routines. The streaming functional encryption scheme enables secure processing of encrypted data streams, allowing for dynamic generation of functional keys and iterative application to ciphertext segments, including those generated prior to key generation.

Abstract: A decentralized multi-authority attribute-based inner-product functional encryption FE (MA-ABIPFE) scheme in the prime-order bilinear groups under target-group-based assumptions is used for encryption. In some embodiments, any party can become an authority and there is no requirement for any global coordination other than the creation of an initial set of common reference parameters.

Abstract: The invention relates to systems, methods, network devices, and machine-readable media for encrypting and decrypting messages in a decentralized multi-authority attribute-based encryption (MA-ABE) scheme for access structures described by monotone LSSS under the decisional bilinear Diffie-Hellman assumptions. The construction can also be modified to obtain an MA-ABE scheme under computational bilinear Diffie-Hellman assumptions.

Abstract: The invention relates to systems, methods, network devices, and machine-readable media for encrypting and decrypting messages in a decentralized multi-authority attribute-based encryption (MA-ABE) scheme for a non-trivial class of access policies whose security is based in the random oracle model solely on the Learning With Errors (LWE) assumption. In some embodiments, any party can become an authority and there is no requirement for any global coordination other than the creation of an initial set of common reference parameters.

Abstract: Adaptively simulation secure functional encryption systems, methods, network devices, and machine-readable media for attribute-weighted sums are implemented. A secret key corresponds to some weight function ƒ, and decryption recovers a weighted sum. The schemes are built upon asymmetric bilinear groups of prime order and the security is derived under the standard (bilateral) k-Linear (k-Lin) assumption.

Abstract: The invention relates to systems, methods, network devices, and machine-readable media for encrypting and decrypting messages in a decentralized multi-authority attribute-based encryption (MA-ABE) scheme that is provably fully-adaptively secure, specifically, secure against an attacker that may corrupt some of the authorities as well as perform key queries adaptively throughout the lifetime of the system.

Abstract: The invention relates to systems, methods, network devices, and machine-readable media for encrypting and decrypting messages in a decentralized multi-authority attribute-based encryption (MA-ABE) scheme for access structures described by monotone LSSS under the decisional bilinear Diffie-Hellman assumptions. The construction can also be modified to obtain an MA-ABE scheme under computational bilinear Diffie-Hellman assumptions.

Abstract: An encryption device (20) generates a ciphertext by setting, in the ciphertext, one of a predicate vector of arithmetic branching programs (ABP) and an attribute vector over a basis B of the basis B and a basis B*, which are dual bases in dual vector spaces. A key generation device (30) generates a decryption key by setting, in the decryption key, the other one of the predicate vector and the attribute vector over the basis B*. A decryption device (40) decrypts the ciphertext by performing a pairing operation on the ciphertext generated by the encryption device (20) and the decryption key generated by the key generation device (30).

Abstract: A signature device (30) acquires a signature key SK(x?) in which an attribute vector x? is set over a basis B* of a basis B and the basis B*, which are dual bases in dual vector spaces. The signature device (30) generates a signature sig for a message MSG by setting predicate information of arithmetic branching programs (ABP) for the signature key SK(x?). The signature device (30) outputs the signature sig and the message MSG to a verification device (40).

Abstract: The invention relates to systems, methods, network devices, and machine-readable media for encrypting and decrypting messages in a decentralized multi-authority attribute-based encryption (MA-ABE) scheme for a non-trivial class of access policies whose security is based in the random oracle model solely on the Learning With Errors (LWE) assumption. In some embodiments, any party can become an authority and there is no requirement for any global coordination other than the creation of an initial set of common reference parameters.

Abstract: A decentralized multi-authority attribute-based inner-product functional encryption FE (MA-ABIPFE) scheme in the prime-order bilinear groups under target-group-based assumptions is used for encryption. In some embodiments, any party can become an authority and there is no requirement for any global coordination other than the creation of an initial set of common reference parameters.

Abstract: A signature device (30) acquires a signature key SK(x?) in which an attribute vector x? is set over a basis B* of a basis B and the basis B*, which are dual bases in dual vector spaces. The signature device (30) generates a signature sig for a message MSG by setting predicate information of arithmetic branching programs (ABP) for the signature key SK(x?). The signature device (30) outputs the signature sig and the message MSG to a verification device (40).

Abstract: An encryption device (20) generates a ciphertext by setting, in the ciphertext, one of a predicate vector of arithmetic branching programs (ABP) and an attribute vector over a basis B of the basis B and a basis B*, which are dual bases in dual vector spaces. A key generation device (30) generates a decryption key by setting, in the decryption key, the other one of the predicate vector and the attribute vector over the basis B*. A decryption device (40) decrypts the ciphertext by performing a pairing operation on the ciphertext generated by the encryption device (20) and the decryption key generated by the key generation device (30).