  Web 3.0 pursues the establishment of decentralized ecosystems based on
blockchain technologies to drive the digital transformation of physical
commerce and governance. Through consensus algorithms and smart contracts in
blockchain, which are based on cryptography technologies, digital identity,
digital asset management, decentralized autonomous organization, and
decentralized finance are realized for secure and transparent digital economy
services in Web 3.0 for promoting the integration of digital and physical
economies. With the rapid realization of quantum devices, Web 3.0 is being
developed in parallel with the deployment of quantum cloud computing and
quantum Internet. In this regard, quantum computing first disrupts the original
cryptographic systems that protect data security while reshaping modern
cryptography with the advantages of quantum computing and communication.
Therefore, this survey provides a comprehensive overview of blockchain-based
Web 3.0 and its quantum and post-quantum enhancement from the ambilateral
perspective. On the one hand, some post-quantum migration methods, and
anti-quantum signatures offer potential ways to achieve unforgeable security
under quantum attack for the internal technologies of blockchain. On the other
hand, some quantum/post-quantum encryption and verification algorithms improve
the external performance of the blockchain, enabling a decentralized, valuable,
secure blockchain system. Finally, we discuss the future directions toward
developing a provable secure decentralized digital ecosystem.
