ycashd v4.4.4

Above all else: Decentralization. Always.

This release enhances decentralization by empowering miners to keep 100% of the block reward after the second halving at block height 2,280,000. (After the second halving, the 5% allocation of the block reward to the Ycash Development Fund will be completely optional.)

This release also eliminates the practice of setting deprecation heights for nodes.

The prior version of ycashd will expire at block height is 2,275,000 (approximately November 21, 2024). You must upgrade to v4.4.4 prior to that block height in order to stay synced to the network.

Special Note for Mining Pools

The release package _MINING_POOLS_ycashd_v4.4.4_wr_linux.tar.gz contains a "witness rework" version meant to streamline mining pool operations. This version requires special instructions if you upgrading from a non-witness-rework version. If you are a mining pool operator interested in this version, ask for additional instructions via the Ycash Discord.

New options available in v4.4.4:

-ydf=integer
The optional percentage of the block reward to donate to the Ycash Development Fund. Default is 5. Set to zero to claim 100% of the block reward.

ycashd v4.4.3

This release introduces a new default transaction fee for shielded transactions, enforced by preventing transactions that significantly underpay the default transaction fee from entering the mempool.

The prior version of ycashd will expire at block height is 1,600,000 (approximately April 11, 2023). You must upgrade to v4.4.3 prior to that block height in order to stay synced to the network.

New Default Fee for Shielded Transactions: 1000 yoshis per shielded output

1. For shielded transactions, the default transaction fee is now 1000 yoshis per shielded output.
2. For the standard shielded transaction with one shielded output and one shielded change output, the default tranaction fee is thus 2000 yoshis.
3. In the future, z_sendmany will be modified to pay the default transaction fee for all transactions. For now, z_sendmany has been modified to pay the default transaction fee for transactions with a large number of shielded outputs.
4. Shielded transactions that underpay the default transaction fee by 50,000 yoshis will be rejected by the mempool. Future versions will like reject tranasctions that underpay by any amount.
5. No change has been made at the consensus layer.
6. It is likely that Ycash will eventually migrate to a Bitcoin-style fee market based in large part on the size of the tranasction in terms of kilobytes (yoshis per kilobyte).

Rescan Required (for most users)

Important note: This version will run full rescan on startup if (1) your wallet.dat is created by an earlier version of ycashd; and (2) there are any shielded keys/addresses stored in it. This is necessary in order to upgrade the witness-related structures stored in local wallet database and get use of implemented optimizations.

Summary of Important Changes

1. New default transaction fee for shielded transactions (see above)
2. Mempool guard that blocks transactions that significantly underpay default transaction fee (see above)
3. Better performance for shielded note decryption
4. Optimizations to full rescan of local wallet
5. Option to skip trial decrypting transactions with a large number of shielded outputs

Special Note for Mining Pools

The release package _MINING_POOLS_ycashd_v4.4.3_wr_linux.tar.gz contains a "witness rework" version meant to streamline mining pool operations. This version requires special instructions if you upgrading from a non-witness-rework version. If you are a mining pool operator interested in this version, ask for additional instructions via the Ycash Discord.

New options available in v4.4.3:

-asyncnotedecryption
Option to toggle parallel Sapling note trial decryption (default: 1)

-skipscanprefork
Skip pre-fork blocks when scanning for wallet transactions (default: 0)

-forcebirthday
Use alternative "wallet birthday" Unix timestamp (default: 0)

-blockprefetch
Use block prefetch to speed up sequential block reading (default: 0)

-prefetchnumthreads=
How many threads to use for parallel block prefetching (default: 8)

-prefetchnumblocks=
How many blocks to keep in prefetch cache (default: 2048)

-ignorespam
Ignore txes with more than or equal to -spamoutputslimit Sapling outputs
(default: 0)

-spamoutputslimit
Per tx Sapling outputs count limit to consider tx a spam when
-ignorespam is used (default: 50)

ycashd v4.4.2

This is the most important release of ycashd in the last two years. It activaties several network upgrades on mainnet at the following block heights:

Blossom: 1,100,000 (approximately Sunday, January 30, 2022)
Heartwood: 1,100,003
Canopy: 1,100,006

(Note: Ycash will only activate the portions of Canopy that are consistent with the founding principles of Ycash.)

The prior version of ycashd will expire at block height is 1,089,998 (approximately Wednesday, January 12, 2022). You must upgrade to v4.4.2 prior to that block height in order to stay synced to the network.

The release package _MINING_POOLS_ycashd_v4.4.2_wr_linux.tar.gz contains a "witness rework" version meant to streamline mining pool operations. This version requires special instructions. If you are a mining pool operator interested in this version, ask for additional instructions via the Ycash Discord.

ycashd v4.4.1

This is a major release. It brings ycashd current with upstream zcashd v4.4.1 and lays the foundation for activating several upstream network upgrades.

The prior version of ycashd will expire at block height is 1,051,920 (approximately Saturday, November 6, 2021). You must upgrade to v4.4.1 prior to that block height in order to stay synced to the network.

This release contains testnet activation blocks heights for the following network upgrades:

Blossom: 661610
Heartwood: 661622
Canopy: 661634

These testnet network upgrades will occur around Saturday, October 30, 2021.

After thoroughly testing the above network upgrades on testnet, the next version will set mainnet activation block heights for those network upgrades.

The release package ycash-v4.4.1-wr-linux.tar.gz contains a "witness rework" version meant to streamline mining pool operations. This version requires special instructions. If you are a mining pool operator interested in this version, ask for additional instructions via the Ycash Discord.

(Note: Ycash will only activate the portions of Canopy that are consistent with the founding principles of Ycash.)

ycashd v2.1.1-6: Further Stability Improvements and Updated Expiry Block Height

This release incorporates an upstream zcashd fix that fixes upstream zcashd issue #4680.

Prior versions versions of ycashd will expire at block height 837,088 (approximately October 27, 2020). You must upgrade to this new version before then in order to stay synced with the blockchain.

The new expiry block height is 1,051,092 (approximately November 4, 2021).

ycashd v2.1.1-5: Stability Improvements

This release incorporates an upstream zcashd fix that fixes upstream zcashd issue #4301, which has plagued Ycash full node operators and Zcash full node operators for months. This issue would cause ycashd to fall to restart due to an assertion failure.

We recommend that all ycashd users upgrade to this release.

Important Note: If you get the following error the first time you run this release:

assertion failure CopyPreviousWitnesses() Assertion (nd->witnessHeight == -1) || (nd->witnessHeight == indexHeight - 1)

it means that you've already encountered the issue the last time that you ran your pre-2.1.1-5 version of ycashd, and you will have to do a full rescan (not a reindex) by passing the -rescan flag to ycashd. For more details, see zcash#4301 (comment).

ycashd v2.1.1-3

This minor release of ycashd incorporates upstream Zcash Pull Request #4379, which fixes upstream Zcash Issue #4301. The issue involved this error message:

Assertion failed: ((nd->witnessHeight == -1) || (nd->witnessHeight == indexHeight - 1)), function CopyPreviousWitnesses, file wallet/wallet.cpp, line 1066.

If you encounter this error message, upgrading to this release should address the problem without requiring a reindex.

We consider this release to be an optional upgrade.

ycashd v2.1.1-2: Bugfix Release

This version of ycashd fixes an issue where some new Ycash nodes were having trouble syncing with the mainnet or testnet.

ycashd v2.1.1

This version of ycashd contains several bug fixes and security fixes, including the softfork fix from upstream zcashd v2.1.1-1.

This is a recommended upgrade. If you are running an older version of ycashd, please upgrade to this version.

ycashd v2.1.0

This new version of ycashd incorporates upstream changes from zcashd v2.1.0 and zcashd v2.1.0-1, but does NOT activate shorter block target spacing (ZIP 208). (Shorter block target spacing is being considered for a future Ycash network upgrade.)

Summary of changes

• Upstream zcashd v2.1.0 and v2.1.0-1 changes
• Fix CVE-2017-18350, upstream from bitcoin
• Fix RPC tests to all run in one script