The paper introduces the concept of dynamic accumulators, which allow for efficient addition and deletion of values while maintaining a short proof of their inclusion. The authors provide a construction of a dynamic accumulator and an efficient zero-knowledge proof of knowledge of an accumulated value, proving its security under the strong RSA assumption. They demonstrate that dynamic accumulators can be used to efficiently revoke anonymous credentials and membership in group signatures and identity escrow schemes. The construction involves incorporating the public key of an accumulator scheme into the group manager's public key and the secret trapdoor into the corresponding secret key. Each time a user joins or leaves the group, the group manager updates the public key and publishes the current accumulator value. The paper also includes a detailed protocol for proving membership in the ACJT identity escrow scheme and the Camenisch-Lysyanskaya credential system, showing how to augment these schemes with membership revocation capabilities. The proposed mechanism does not significantly increase the communication or computation overhead compared to the underlying schemes.The paper introduces the concept of dynamic accumulators, which allow for efficient addition and deletion of values while maintaining a short proof of their inclusion. The authors provide a construction of a dynamic accumulator and an efficient zero-knowledge proof of knowledge of an accumulated value, proving its security under the strong RSA assumption. They demonstrate that dynamic accumulators can be used to efficiently revoke anonymous credentials and membership in group signatures and identity escrow schemes. The construction involves incorporating the public key of an accumulator scheme into the group manager's public key and the secret trapdoor into the corresponding secret key. Each time a user joins or leaves the group, the group manager updates the public key and publishes the current accumulator value. The paper also includes a detailed protocol for proving membership in the ACJT identity escrow scheme and the Camenisch-Lysyanskaya credential system, showing how to augment these schemes with membership revocation capabilities. The proposed mechanism does not significantly increase the communication or computation overhead compared to the underlying schemes.