📅 Original date posted:2016-02-29 📝 Original message:-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Hi I’ve been thinking around a solution to reduce nodes bootstrap time (IBD) as well as a way to reduce the amount of bandwidth/network usage per node. Not sure if this idea was/is already discussed, haven’t found anything in a quick research. ==Title== Fast bootstrapping with a pre-generated UTXO-set database. ==Abstract== This documents describes a way how bitcoin nodes can bootstrap faster by loading a pre-generated UTXO-set datafile with moderate reduction of the security model. ==Specification== Bitcoin-core or any other full node client will need to provide a feature to "freeze" the UTXO-set at a specified height (will require a reindex). The frozen UTXO-set – at a specific height – will be deterministic linearized in a currently not specified data-serializing-format. Additionally, a serialized form of the current chain-index (chain containing all block-headers) up to the specified height will be appended to the pre-generated UTXO-set-datafile. The datafile will be hashed with a double SHA256. The corresponding hash will be produced/reproduced and signed (ECDSA) by a group of developers, ideally the same group of developers who are also signing deterministic builds (binary distribution). Full node client implementations that supports bootstrapping from a pre-generated UTXO-set, need to include... 1.) a set of pubkeys from trusted developers 2.) the hash (or hashes) of the pre-generated UTXO-set-datafile(s) 3.) n signatures of the hash(es) from 2) from a subset of developers defined in 1) To guarantee the integrity of developers pubkeys & signatures, methods like the current gitian build, used in bitcoin-core, must be used. New nodes could download a copy of the pre-generated UTXO-set, hash it, verify the hash against the allowed UTXO-sets, verify the ECDSA signatures from various developers, and continue bootstrapping from the specified height if the users accepts the amount of valid signatures . Sharing of the pre-generated UTXO-set can be done over CDNs, bit-torrent or any other file hosting solution. It would also be possible to extend the bitcoin p2p layer with features to distribute/share a such pre-generated UTXO-set, in chunks and with the according hashes to detect invalidity before downloading the whole content (but would probably end up in something very similar to bit-torrent). - ---------------------- </jonas> -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJW1B1wAAoJECnUvLZBb1PsqzsP/iSdvyhUzy+BZVSZbKXNjk5P 2vrtirI6NvKQd8hHbrcFeLfyswzYc2JWRnX8sATlauIS0pYdr97JriwUGlvxvNrY iVTDdf8MIVu8zScLQtJbMatpMvsewtqQEidn/yxWIhiCg4G2T5DZmlBU6O4XIKR6 5aPHElGOKZ15EWGHBG7z4owj3MiOaxhD9q5erBbfLPpcm08o6XAv5miqmGnnn3zh gocg4Gxs6iDygh3b2dCJFwWIVPxF6UVJhyjv2kLZUmEHT2Y2QvdGcLIIewcWHDze kgoZYmOEowujCbmeJ+LBwgOI0c1N6L/ciomPBne7ILmK4LyUEzyMLJKNYf/sZ8vI sVlmwZwZZLfILC7mzMAM0pfj99IOW680WHch9v31lWFlxW/bLvLqAO7n3acQuD6s xCZN2nAhmWC8FnMFxqB3EUz0lX8giV3qRJZjbQMS+ZrngYkAmVv2bAsoLndqf6MO l9W8B+ICg1KZLGIOF2pUrInpkB6gUALDFnypV4CeIVdeqtk5l4LnCHK6c4++Hl5n Bv5HQ/wTgKKNFtHBEJpWyYWvAjfFtgUZUKblR+Bh+D7/Gte1ehiYd02KYD4ds9Y4 3gfO8YbAz/I14Yuh2bIlvVKPWnLQBwL5BBioBfvmhV/r6rEpzWvB7H6Fmi1c759l VlL0GiUV8ar2LlFhEmWk =lZSy -----END PGP SIGNATURE-----