The four-volume proceedings set LNCS 14601-14604 constitutes the refereed proceedings of the 27th IACR International Conference on Practice and Theory of Public Key Cryptography, PKC 2024, held in Sydney, NSW, Australia, April 15–17, 2024. The 54 papers included in these proceedings were carefully reviewed and selected from 176 submissions. They focus on all aspects of signatures; attacks; commitments; multiparty computation; zero knowledge proofs; theoretical foundations; isogenies and applications; lattices and applications; Diffie Hellman and applications; encryption; homomorphic encryption; and implementation.