We present an anonymous certification scheme that provides data minimization to allow the learners of an e-assessment platform to reveal only required information to certificate authority providers. Attribute-based signature schemes are considered as a promising cryptographic primitive for building privacy-preserving attribute credentials, also known as anonymous credentials. These mechanisms allow the derivation of certified attributes by the issuing authority relying on non-interactive protocols and enable end-users to authenticate with verifiers in a pseudonymous manner, e.g., by providing only the minimum amount of information to service providers