Blockchain technology has significantly impacted digital transactions and data management by providing a decentralized, transparent, and immutable ledger. Private blockchains, unlike public blockchains, are restricted to a pre-selected group of participants, making them more suitable for controlled environments such as enterprises, governments, or academic institutions. Hyperledger Fabric (HLF) is a widely used framework for private blockchain technology, designed for enterprise use.

With quantum computers on the rise, commonly used cryptographic algorithms are increasingly at risk of becoming obsolete. Blockchain networks rely extensively on these primitives, making them particularly vulnerable to advances in quantum computing. To counter this vulnerability, post-quantum algorithms have gained popularity within the cryptographic community.

This thesis focuses on securing private blockchains built on HLF against potential quantum adversaries using post-quantum cryptographic primitives. We implement ML-DSA, Vesper, and TDUE as smart contracts for digital signing, zero-knowledge proofs, and updatable encryption, respectively, and report on their performance. Furthermore, we build on top of Fabric Private Chaincode to maintain the confidentiality of the contract application state. While overall performance is not yet competitive with classical cryptographic primitives, our findings indicate that post-quantum primitives have promising potential for use in private blockchains.