[DRepTalk test] Lower utxoCostPerByte to the guardrail minimum of 3,000
On-chain changes
- EconomicUTxO cost per byte4,310 lovelace/byte→3,000 lovelace/byte
UTxO cost per byte
Abstract
This preprod test proposal lowers utxoCostPerByte from 4,310 to 3,000 lovelace per byte, the lowest value the constitution allows. It checks that a parameter change for a security-relevant parameter can be built, passes the constitution’s guardrails script and goes to a vote of DReps, the Constitutional Committee and stake pools. A wallet would then ask for about 0.69 ada instead of 1.00 ada when sending plain ada.
Changes:
- UTxO cost per byte: 4,310 lovelace/byte to 3,000 lovelace/byte. The constitution allows 3,000 lovelace/byte to 6,500 lovelace/byte.
Motivation & rationale
utxoCostPerByte sets the minimum ada every new output has to hold. On mainnet it has been 4,310 lovelace per byte for a long time, while the constitution allows 3,000 to 6,500. Tooling that lets the community propose and judge a change to it needs to be tested end to end before such a proposal is made on mainnet. This action tests the lower bound of that range and carries no recommendation for mainnet.
The value 3,000 is the lower bound set by UCPB-01, so it is the largest reduction the guardrails script accepts. With outputs sized the way wallets size them, the minimum for a plain ada output goes from about 0.996 to 0.693 ada, for an output with one native token from about 1.190 to 0.828 ada, and for an output with a 10 KB reference script from about 45.18 to 31.45 ada. Fees do not change, and existing UTxOs keep their ada because the minimum is only checked when an output is created.
utxoCostPerByte is critical to the operation of the blockchain, so stake pools vote on it (PARAM-03a). The constitution asks that at least 90 days normally pass between publishing an off-chain proposal and submitting the action (PARAM-04a). This preprod test does not follow that period. A mainnet proposal should.
A real proposal would also have to address UCPB-05a: the acceptable cost and time of an attack on UTxO storage, the memory needs of full node operators, typical UTxO sizes and current node memory usage. At the lower bound these weigh most, because the protection against cheap UTxO growth is weakest there.