# Verkle Trees - Preimages generation & distribution --- ## Why is this relevant for the Verkle conversion? - We have to migrate all the data from MPT to VKT - The keys in MPT are hashed - We need the preimage of the hash to rekey it into the VKT - Thus, **we need all the preimages of the MPT tree** --- ## Overlay Tree overview & timeline mental model  --- ## Current proposed strategy  --- ## How to decide the right moment for Slot C? --- ## Database generation and validation - Who generates the database? (TBD) - Can people easily verify it? (Yes) --- ## Database format - Can be easy and efficient - Flat file with [20 byte | 32 byte] ordered values - No lookups, sequential read in the exact expected order - Redundancy? --- ## How is the database distributed? - Out of protocol: - Multiple independent CDNs - Torrent - In protocol: - Build sub-protocol allowing clients to share file through peers --- ## Most important question - **How we distribute the preimage database? (In-protocol or out-protocol?)**