RSAta

RSAta is a theoretical cryptographic framework that extends RSA cryptography to support attribute-based authentication and access control. It combines the RSA public-key system with an attribute-based policy mechanism, enabling encryption and signatures that are tied to user attributes rather than to identities alone.

In a typical RSAta deployment, a trusted authority issues attribute credentials to users. Data is encrypted under an access policy expressed as a Boolean combination of attributes; decryption is possible only for holders whose attribute set satisfies the policy. A separate signing variant allows a signer to attach attributes to a signature, and verifiers check that the signer possessed the required attributes at signing time.

The construction relies on standard RSA primitives for public-key operations, augmented with policy encoding and attribute keys. Upstream steps include a setup algorithm generating a public/modulus pair, an attribute-key generation procedure, an encryption procedure that embeds a policy, and a decryption procedure that checks attribute satisfaction. Security is typically analyzed under RSA hardness assumptions; the scheme can be designed to achieve CPA or CCA security depending on the design.

Applications include cloud-based access control, secure data sharing, and IoT device provisioning, where fine-grained, auditable access is needed. RSAta offers revocation by updating attribute credentials or policy definitions, though revocation can be complex and may require re-encrypting data or distributing fresh keys. Performance overhead grows with policy size and the number of attributes.

Further research and standardization are ongoing, with related work in attribute-based encryption and functional encryption providing context for RSAta's approach. See also RSA, attribute-based encryption, functional encryption, threshold cryptography, digital signatures.