zec
/
zips
mirror of https://github.com/zcash/zips.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Address remaining comments, clean up references

This commit is contained in:
str4d 2018-02-28 22:15:12 +00:00
parent c48da32f5f
commit 10f83c790f
No known key found for this signature in database
GPG Key ID: 665DBCD284F7DAFF
1 changed files with 10 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
drafts/str4d-overwinter-activation/draft1.rst
View File

@ -81,7 +81,7 @@ BRANCH_ID
ACTIVATION_HEIGHT
The non-zero block height at which the network upgrade rules will come into effect, and be enforced as part
of the blockchain consensus.
of the block chain consensus.
For removal of ambiguity, the block at height ``ACTIVATION_HEIGHT - 1`` is subject to the pre-upgrade
consensus rules, and would be the last common block in the event of a persistent pre-upgrade branch.
@ -105,12 +105,7 @@ the ``BRANCH_ID`` MUST also be changed.
Activation mechanism
--------------------
A blockchain is defined as invalid if, within the set of all network upgrades that have activated in the past
(or will activate in future) on that chain, an ``ACTIVATION_HEIGHT`` is repeated. Note that this does not
require ``ACTIVATION_HEIGHT`` to be globally unique, or even locally unique; multiple network upgrades can
occur in parallel, as long as they are non-overlapping (only one will activate on any given chain).
Concretely, this means that the Zcash blockchain is broken into "epochs" of block height intervals
The Zcash block chain is broken into "epochs" of block height intervals
``[ACTIVATION_HEIGHT_N, ACTIVATION_HEIGHT_{N+1})`` (i.e. including ``ACTIVATION_HEIGHT_N`` and excluding
``ACTIVATION_HEIGHT_{N+1}``), on which consensus rule sets are defined.
@ -153,13 +148,8 @@ Post-activation upgrading
If a user does not upgrade their node to a compatible software version before ``ACTIVATION_HEIGHT`` is
reached, their node will follow any pre-upgrade branch that persists, and may download blocks that are
incompatible with the post-upgrade branch. If the user subsequently upgrades their node to a compatible
software version, the node will consider these blocks to be invalid, and MUST take one of the two following
actions:
- Discard all blocks of height ``ACTIVATION_HEIGHT`` and above, and then synchronize with the network.
- Shut down and alert the user of the issue. In this case, the node could offer an option to perform the first
action.
software version, the node will consider these blocks to be invalid, and if there are a significant number of
invalid blocks it SHOULD shut down and alert the user of the issue.
Memory pool
-----------
@ -174,8 +164,8 @@ Two-way replay protection
-------------------------
Before the Overwinter network upgrade, two-way replay protection is ensured by enforcing post-upgrade that the
most significant bit of the transaction version is set to 1. [#zip-tx-format]_ From the perspective of old
nodes, the transactions will have a negative version number, which is invalid under the old consensus rules.
most significant bit of the transaction version is set to 1. [#zip-0202]_ From the perspective of old nodes,
the transactions will have a negative version number, which is invalid under the old consensus rules.
Enforcing this rule trivially makes old transactions invalid on the Overwinter branch.
After the Overwinter network upgrade, two-way replay protection is ensured by transaction signatures
@ -200,7 +190,7 @@ the ``BRANCH_ID``.
Deployment
==========
This proposal will be deployed with the Overwinter network upgrade.
This proposal will be deployed with the Overwinter network upgrade. [#zip-0201]_
Backward compatibility
@ -226,5 +216,6 @@ References
.. [#release-lifecycle]
- https://z.cash/blog/release-cycle-and-lifetimes.html
- https://z.cash/blog/release-cycle-update.html
.. [#zip-tx-format] `Overwinter Transaction Format <https://github.com/zcash/zips/pull/133>`_
.. [#zip-0143] `Transaction Signature Verification for Overwinter <https://github.com/zcash/zips/pull/129>`_
.. [#zip-0202] `ZIP 202: Version 3 Transaction Format for Overwinter <https://github.com/zcash/zips/pull/133>`_
.. [#zip-0143] `ZIP 143: Transaction Signature Verification for Overwinter <https://github.com/zcash/zips/pull/129>`_
.. [#zip-0201] `ZIP 201: Network Peer Management for Overwinter <https://github.com/zcash/zips/pull/134>`_