The speaker begins by introducing himself as a long-time contributor to a project focused on incremental backup, image transfer, and NBD tools. He explains the need for disk image checksums, particularly when dealing with different formats and storage systems. The speaker introduces the blockchain command, which is optimized for disk images, and the block hash library, which can be used to integrate the functionality into other programs. He demonstrates the use of the tools and highlights their speed and efficiency compared to standard tools like SHA-SUM. The speaker concludes by discussing how to contribute to the project and mentioning potential future developments, like adding support for other image formats and integrating the tools into different systems. During the Q&A session, the speaker answers questions about handling zero blocks, adding new checksum algorithms, and testing cryptographic algorithms.