Abstract—This work presents a zero-knowledge credential framework designed to enable secure and privacy-preserving attribute verification across multiple independent systems. Theframework allows a user to prove statements of the form a ≥ t,where a ∈ Zq represents a secret attribute and t denotes a public threshold, without revealing the attribute value itself. At the sametime, the framework prevents the exposure of any globally stable identifier, thereby eliminating the risk of cross-domain tracking. The construction is based on Pedersen commitments, where each attribute is encoded as C = g^ah^r ∈ G, with G ⊆ Z^∗p denoting a cyclic group of prime order q. The generators g and h are selected such that the discrete logarithm relation between them is unknown. This ensures that the commitment is computationally binding under the discrete logarithm assumption and perfectly hiding due to the use of randomness r. As a result, the committed attribute remains concealed while still allowing verification of statements about it. Predicate verification is achieved using a sigma protocol, whichenables the prover to demonstrate knowledge of valid witnesses without revealing them. In particular, the protocol proves the relation C · g−t = g^δh^r, where δ = a − t. This transformation allows the system to verify threshold conditions such as a ≥ twithout disclosing the value of a. The zero-knowledge property of the protocol ensures that the verifier learns only the validity ofthe statement and no additional information about the underlying attribute or randomness.To prevent correlation of user activity across different verification domains, the framework introduces scoped pseudonyms defined as IDS = pkH(S), where pk = g^x is a public key derivedfrom a secret key x, and H is a cryptographic hash functionmodeled as a random oracle. The scope S represents a domain specific identifier. This construction produces a unique identifierfor each domain while ensuring that identifiers generated for different scopes cannot be linked without solving the discrete logarithm problem in G. Revocation is supported through an RSA accumulator constructed under the Strong RSA assumption. For a revoked set R={ri}, the accumulator value is defined as A = g^Qri mod N,where N is an RSA modulus. The system enables efficient non membership verification using witnesses derived from B´ezout coefficients1. This mechanism allows a verifier to confirm thata credential has not been revoked, while maintaining constant verification cost that does not depend on the size of the revokedset. Importantly, this process does not introduce any additional identifiers that could compromise user privacy.The framework follows a complete lifecycle consisting of system setup, credential issuance, proof generation, scoped identifier derivation, verification, and revocation checking. During issuance, attributes are committed and signed by an issuer, producing a credential that can later be used by the holder. During authentication, the holder generates a non-interactive zero-knowledge proof bound to a verifier-specific challenge, ensuring freshness and resistance to replay attacks. The verifier evaluates the proof, validates the credential, and performs revocation checks without accessing any underlying attribute values. The security of the system is grounded in well-established cryptographic assumptions, including the discrete logarithm assumption in prime-order groups, the Strong RSA assumption for accumulator security, and the random oracle model for hash functions. Under these assumptions, the framework providesattribute privacy, soundness of predicate proofs, scoped unlinkability across verification domains, and resistance to replay and collusion-based inference attacks. The complete protocol stack has been implemented using 2048-bit security parameters within a modular architecture that includes issuer, holder, and multiple verifier components. The system is designed to be compatible with decentralized identity frameworks through the integration of decentralized identifiers (DID) and verifiable credentials (VC). Experimental evaluationdemonstrates that the framework achieves an average verification latency below 3 milliseconds, a compact presentation size ofapproximately 3 kilobytes, and stable revocation verification performance for revoked sets containing up to 200 elements.The proposed framework demonstrates that selective disclosure, strong unlinkability, and efficient revocation can be achieved simultaneously without relying on pairing-based cryptographyor trusted setup assumptions. The modular structure allowsindependent evolution of system components while maintainingconsistent security guarantees. This makes the system suitablefor practical deployment in multi-system identity verificationscenarios where both security and privacy are essential.Index Terms—Zero-knowledge proofs, Attribute-based credentials, Selective disclosure, Unlinkability, RSA accumulator,Pedersen commitments, Sigma protocols, Decentralized identity,Verifiable credentials