Add snapshot booting proposal

book/src/SUMMARY.md

@@ -55,6 +55,7 @@
   * [Inter-chain Transaction Verification](proposals/interchain-transaction-verification.md)
   * [Snapshot Verification](proposals/snapshot-verification.md)
   * [Bankless Leader](proposals/bankless-leader.md)
+  * [Booting from a Snapshot](proposals/booting-from-snapshot.md)
 * [Implemented Design Proposals](implemented-proposals/README.md)
   * [Blocktree](implemented-proposals/blocktree.md)
   * [Cluster Software Installation and Updates](implemented-proposals/installer.md)

book/src/proposals/booting-from-snapshot.md

@@ -0,0 +1,21 @@
+# Booting From a Snapshot
+
+## Problem
+
+A validator booting from a snapshot should know that they are caught up to the cluster before voting.
+
+## Solution
+
+A booting validator needs to have some set of trusted validators whose votes it will rely upon to ensure that it has caught up to the cluster and has a valid snapshot. With that set, the validator can
+
+1. Get a snapshot to boot from.
+
+2. Send canary transactions with its local recent blockhash to test if they get onto the ledger.
+
+3. While waiting to see one of the canary transactions, set a new root every time some threshold percent of the trusted validator stake roots a bank.
+
+4. Once a canary transaction is observed in a bank that some threshold of trusted validator stake has voted on, confirm that the `trusted validator root` > `snapshot root`
+
+5. Figure out what banks the validator is not locked out from. This is not currently done, and should be addressed separately, but is not necessary for this design.
+
+6. Start voting.