Merge pull request bitcoin#1104 from ajtowns/202103-bip341-speedy-trial-mtp

BIP341: speedy trial activation parameters

Author: luke-jr

bip-0341.mediawiki

@@ -292,7 +292,43 @@ The test vectors used in the [https://github.com/bitcoin/bitcoin/blob/3820090bd6
 
 == Deployment ==
 
-TODO
+This BIP is deployed concurrently with [[bip-0342.mediawiki|BIP342]].
+
+For Bitcoin signet, these BIPs are always active.
+
+For Bitcoin mainnet and testnet3, these BIPs will be deployed by "version bits" with the name "taproot" and bit 2, using [[bip-0009.mediawiki|BIP9]] modified to use a lower threshold, with an additional ''min_activation_height'' parameter and replacing the state transition logic for the DEFINED, STARTED and LOCKED_IN states as follows:
+
+    case DEFINED:
+        if (GetMedianTimePast(block.parent) >= starttime) {
+            return STARTED;
+        }
+        return DEFINED;
+
+    case STARTED:
+        int count = 0;
+        walk = block;
+        for (i = 0; i < 2016; i++) {
+            walk = walk.parent;
+            if ((walk.nVersion & 0xE0000000) == 0x20000000 && ((walk.nVersion >> bit) & 1) == 1) {
+                count++;
+            }
+        }
+        if (count >= threshold) {
+            return LOCKED_IN;
+        } else if (GetMedianTimePast(block.parent) >= timeout) {
+            return FAILED;
+        }
+        return STARTED;
+
+    case LOCKED_IN:
+        if (block.nHeight < min_activation_height) {
+            return LOCKED_IN;
+        }
+        return ACTIVE;
+
+For Bitcoin mainnet, the starttime is epoch timestamp 1619222400 (midnight 24 April 2021 UTC), timeout is epoch timestamp 1628640000 (midnight 11 August 2021 UTC), the threshold is 1815 blocks (90%) instead of 1916 blocks (95%), and the min_activation_height is block 709632 (expected approximately 12 November 2021).
+
+For Bitcoin testnet3, the starttime is epoch timestamp 1619222400 (midnight 24 April 2021 UTC), timeout is epoch timestamp 1628640000 (midnight 11 August 2021 UTC), the threshold is 1512 blocks (75%), and the min_activation_height is block 0.
 
 == Backwards compatibility ==
 As a soft fork, older software will continue to operate without modification.

bip-0342.mediawiki

@@ -133,6 +133,10 @@ In addition to changing the semantics of a number of opcodes, there are also som
 
 <references />
 
+==Deployment==
+
+This proposal is deployed identically to Taproot ([[bip-0341.mediawiki|BIP341]]).
+
 ==Examples==
 
 The Taproot ([[bip-0341.mediawiki|BIP341]]) test vectors also contain examples for Tapscript execution.