Explore fine-grained cryptography in this invited talk from Eurocrypt 2020. Delve into the intricacies of public key encryption, cryptographic problem-solving, and the motivations behind fine-grained cryptography. Examine the structure and plan of this emerging field, focusing on polynomial problems, proof of work systems, and MA proof systems. Analyze batch evaluation techniques and their complexity implications. Gain insights into other relevant results in the domain and understand the broader context of fine-grained cryptography as a new frontier in cryptographic research.