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Table of Contents
This RFC proposes to change the duration of the Confirmation Period for the Big Tipper and Small Tipper tracks in Polkadot OpenGov:
Small Tipper: 10 Minutes -> 12 Hours
Big Tipper: 1 Hour -> 1 Day
Currently, these are the durations of treasury tracks in Polkadot OpenGov. Confirmation periods for the Spender tracks were adjusted based on RFC20 and its related conversation.
You can see that there is a general trend on the Spender track that when the privilege level (the amount the track can spend) the confirmation period approximately doubles.
I believe that the Big Tipper and Small Tipper track's confirmation periods should be adjusted to match this trend.
In the current state it is possible to somewhat positively snipe these tracks, and whilst the power/privilege level of these tracks is very low (they cannot spend a large amount of funds), I believe we should increase the confirmation periods to something higher. This is backed up by the recent sentiment in the greater community regarding referendums submitted on these tracks. The parameters of Polkadot OpenGov can be adjusted based on the general sentiment of token holders when necessary.
The primary stakeholders of this RFC are: -– DOT token holders – as this affects the protocol's treasury -– Entities wishing to submit a referendum on these tracks – as this affects the referendum's timeline -– Projects with governance app integrations – see Performance, Ergonomics and Compatibility section below
This RFC proposes to change the duration of the confirmation period for both the Big Tipper and Small Tipper tracks. To achieve this the confirm_period parameter for those tracks should be changed.
confirm_period
You can see the lines of code that need to be adjusted here:
Big Tipper: https://github.com/polkadot-fellows/runtimes/blob/f4c5d272d4672387771fb038ef52ca36f3429096/relay/polkadot/src/governance/tracks.rs#L245
Small Tipper: https://github.com/polkadot-fellows/runtimes/blob/f4c5d272d4672387771fb038ef52ca36f3429096/relay/polkadot/src/governance/tracks.rs#L231
This RFC proposes to change the confirm_period for the Big Tipper track to DAYS (i.e. 1 Day) and the confirm_period for the Small Tipper track to 12 * HOURS (i.e. 12 Hours).
DAYS
12 * HOURS
The drawback of changing these confirmation periods is that the lifecycle of referenda submitted on those tracks would be ultimately longer, and it would add a greater potential to negatively "snipe" referenda on those tracks by knocking the referendum out of its confirmation period once the decision period has ended. This can be a good or a bad thing depending on your outlook of positive vs negative sniping.
This referendum will enhance the security of the protocol as it relates to its treasury. The confirmation period is one of the last lines of defense for the Polkadot token holder DAO to react to a potentially bad referendum and vote NAY in order for its confirmation period to be aborted.
This is a simple change (code wise) that should not affect the performance of the Polkadot protocol, outside of increasing the duration of the confirmation periods for these 2 tracks.
As per the implementation of changes described in RFC-20, it was identified that governance UIs automatically update to meet the new parameters:
N/A
Some token holders may want these confirmation periods to remain as they are currently and for them not to increase. If this is something that the Polkadot Technical Fellowship considers to be an issue to implement into a runtime upgrade then I can create a Wish For Change to obtain token holder approval.
The parameters of Polkadot OpenGov will likely continue to change over time, there are additional discussions in the community regarding adjusting the min_support for some tracks so that it does not trend towards 0%, similar to the current state of the Whitelisted Caller track. This is outside of the scope of this RFC and requires a lot more discussion.
min_support
This RFC proposes the integration of smart contracts on the Coretime chain to enhance flexibility and enable complex decentralized applications, including secondary market functionalities.
Currently, the Coretime chain lacks the capability to support smart contracts, which limits the range of decentralized applications that can be developed and deployed. By enabling smart contracts, the Coretime chain can facilitate more sophisticated functionalities such as automated region trading, dynamic pricing mechanisms, and other decentralized applications that require programmable logic. This will enhance the utility of the Coretime chain, attract more developers, and create more opportunities for innovation.
Additionally, while there is a proposal (#885) to allow EVM-compatible contracts on Polkadot’s Asset Hub, the implementation of smart contracts directly on the Coretime chain will provide synchronous interactions and avoid the complexities of asynchronous operations via XCM.
Primary stakeholders include:
This RFC introduces the following key components:
There are several drawbacks to consider:
This RFC proposes a new instruction that provides a way to initiate on remote chains, asset transfers which transfer multiple types (teleports, local-reserve, destination-reserve) of assets, using XCM alone.
The currently existing instructions are too opinionated and force each XCM asset transfer to a single transfer type (teleport, local-reserve, destination-reserve). This results in inability to combine different types of transfers in single transfer which results in overall poor UX when trying to move assets across chains.
XCM is the de-facto cross-chain messaging protocol within the Polkadot ecosystem, and cross-chain assets transfers is one of its main use-cases. Unfortunately, in its current spec, it does not support initiating on a remote chain, one or more transfers that combine assets with different transfer types. @@ -642,14 +551,14 @@ For example, allows single XCM program execution to transfer multiple assets fro Kusama Asset Hub, over the bridge through Polkadot Asset Hub with final destination ParaP on Polkadot.
ParaP
With current XCM, we are limited to doing multiple independent transfers for each individual hop in order to move both "interesting" assets, but also "supporting" assets (used to pay fees).
A new instruction InitiateAssetsTransfer is introduced that initiates an assets transfer from the chain it is executed on, to another chain. The executed transfer is point-to-point (chain-to-chain) with all of the transfer properties specified in the instruction parameters. The instruction also @@ -837,9 +746,9 @@ by executing a single XCM message, even though we'll be mixing multiple ).unwrap(); }) } -
InitiateAssetsTransfer
No drawbacks identified.
There should be no security risks related to the new instruction from the XCVM perspective. It follows the same pattern as with single-type asset transfers, only now it allows combining multiple types at once.
Improves security by enabling @@ -848,11 +757,11 @@ which minimizes the potential free/unpaid work that a receiving chain has to do. required execution fee payment, part of the instruction logic through the remote_fees: Option<AssetTransferFilter> parameter, which will make sure the remote XCM starts with a single-asset-holding-loading-instruction, immediately followed by a BuyExecution using said asset.
remote_fees: Option<AssetTransferFilter>
BuyExecution
This brings no impact to the rest of the XCM spec. It is a new, independent instruction, no changes to existing instructions.
Enhances the exposed functionality of Polkadot. Will allow multi-chain transfers that are currently forced to happen in multiple programs per asset per "hop", to be possible in a single XCM program.
No performance changes/implications.
The proposal enhances developers' and users' cross-chain asset transfer capabilities. This enhancement is optimized for XCM @@ -866,11 +775,11 @@ success. A program where the new instruction is used to initiate multiple types of asset transfers, cannot be downgraded to older XCM versions, because there is no equivalent capability there. Such conversion attempts will explicitly fail.
None.
Elastic scaling is not resilient against griefing attacks without a way for a PoV (Proof of Validity) to commit to the particular core index it was intended for. This RFC proposes a way to include core index information in the candidate commitments and the CandidateDescriptor data structure in a backwards compatible way. Additionally it proposes the addition of a SessionIndex field in the CandidateDescriptor to make dispute resolution more secure and robust.
CandidateDescriptor
SessionIndex
This RFC proposes a way to solve two different problems:
This approach and alternatives have been considered and discussed in this issue.
The approach proposed below was chosen primarily because it minimizes the number of breaking changes, the complexity and takes less implementation and testing time. The proposal is to change the existing primitives while keeping binary compatibility with the older versions. We repurpose @@ -1098,15 +1007,15 @@ be able to detect the version of a given candidate receipt.
The version of the descriptor is detected by checking if the version field is 0 and the reserved fields are zeroed. If this is true it means the descriptor is version 2, otherwise we consider it is version 1.
version
0
The only drawback is that further additions to the descriptor are limited to the amount of remaining unused space.
Standard testing (unit tests, CI zombienet tests) for functionality and mandatory security audit to ensure the implementation does not introduce any new security issues.
Backwards compatibility of the implementation will be tested on testnets (Versi and Westend).
There is no impact on privacy.
The expected performance impact is negligible for sending and processing the new UMP message in the runtime as well as on the node side.
The ClaimQueueOffset along with the relay parent choice allows parachains to optimize their @@ -1139,12 +1048,12 @@ candidate receipts and verify the CoreIndex and SessionIndex< Any tooling that decodes UMP XCM messages needs an update to support or ignore the new UMP messages, but they should be fine to decode the regular XCM messages that come before the separator. -Prior Art and References +Prior Art and References Forum discussion about a new CandidateReceipt format: https://forum.polkadot.network/t/pre-rfc-discussion-candidate-receipt-format-v2/3738 -Unresolved Questions +Unresolved Questions N/A -Future Directions and Related Material +Future Directions and Related Material The implementation is extensible and future proof to some extent. With minimal or no breaking changes, additional fields can be added in the candidate descriptor until the reserved space is exhausted @@ -1186,7 +1095,7 @@ by using the version field of the descirptor introduced in this RFC AuthorsFrancisco Aguirre -Summary +Summary XCM already handles execution fees in an effective and efficient manner using the BuyExecution instruction. However, other types of fees are not handled as effectively -- for example, delivery fees. Fees exist that can't be measured using Weight -- as execution fees can -- so a new method should be thought up for those cases. @@ -1195,7 +1104,7 @@ This RFC proposes making the fee handling system simpler and more general, by do Adding a fees register Deprecating BuyExecution and adding a new instruction PayFees with new semantics to ultimately replace it.
ClaimQueueOffset
CoreIndex
SessionIndex< Any tooling that decodes UMP XCM messages needs an update to support or ignore the new UMP messages, but they should be fine to decode the regular XCM messages that come before the separator. -Prior Art and References +Prior Art and References Forum discussion about a new CandidateReceipt format: https://forum.polkadot.network/t/pre-rfc-discussion-candidate-receipt-format-v2/3738 -Unresolved Questions +Unresolved Questions N/A -Future Directions and Related Material +Future Directions and Related Material The implementation is extensible and future proof to some extent. With minimal or no breaking changes, additional fields can be added in the candidate descriptor until the reserved space is exhausted @@ -1186,7 +1095,7 @@ by using the version field of the descirptor introduced in this RFC AuthorsFrancisco Aguirre -Summary +Summary XCM already handles execution fees in an effective and efficient manner using the BuyExecution instruction. However, other types of fees are not handled as effectively -- for example, delivery fees. Fees exist that can't be measured using Weight -- as execution fees can -- so a new method should be thought up for those cases. @@ -1195,7 +1104,7 @@ This RFC proposes making the fee handling system simpler and more general, by do Adding a fees register Deprecating BuyExecution and adding a new instruction PayFees with new semantics to ultimately replace it.
Any tooling that decodes UMP XCM messages needs an update to support or ignore the new UMP messages, but they should be fine to decode the regular XCM messages that come before the separator.
Forum discussion about a new CandidateReceipt format: https://forum.polkadot.network/t/pre-rfc-discussion-candidate-receipt-format-v2/3738
CandidateReceipt
The implementation is extensible and future proof to some extent. With minimal or no breaking changes, additional fields can be added in the candidate descriptor until the reserved space is exhausted
XCM already handles execution fees in an effective and efficient manner using the BuyExecution instruction. However, other types of fees are not handled as effectively -- for example, delivery fees. Fees exist that can't be measured using Weight -- as execution fees can -- so a new method should be thought up for those cases. @@ -1195,7 +1104,7 @@ This RFC proposes making the fee handling system simpler and more general, by do
Weight
fees
PayFees
Execution fees are handled correctly by XCM right now. However, the addition of extra fees, like for message delivery, result in awkward ways of integrating them into the XCVM implementation. This is because these types of fees are not included in the language. @@ -1203,14 +1112,14 @@ The standard should have a way to correctly deal with these implementation speci The new instruction moves the specified amount of fees from the holding register to a dedicated fees register that the XCVM can use in flexible ways depending on its implementation. The XCVM implementation is free to use these fees to pay for execution fees, transport fees, or any other type of fee that might be necessary. This moves the specifics of fees further away from the XCM standard, and more into the actual underlying XCVM implementation, which is a good thing.
The new instruction that will replace BuyExecution is a much simpler and general version: PayFees. This instruction takes one Asset, takes it from the holding register, and puts it into a new fees register. The XCVM implementation can now use this Asset to make sure every necessary fee is paid for, this includes execution fees, delivery fees, and any other type of fee @@ -1241,12 +1150,12 @@ BuyExecution { asset, weight_limit } PayFees { asset } // ...rest } -
Asset
There needs to be an explicit change from BuyExecution to PayFees, most often accompanied by a reduction in the assets passed in.
It might become a security concern if leftover fees are trapped, since a lot of them are expected.
There should be no performance downsides to this approach. The fees register is a simplification that may actually result in better performance, in the case an implementation is doing a workaround to achieve what this RFC proposes.
This RFC can't just change the semantics of the BuyExecution instruction since that instruction accepts any funds, uses what it needs and returns the rest immediately. The new proposed instruction, PayFees, doesn't return the leftover immediately, it keeps it in the fees register. In practice, the deprecated BuyExecution needs to be slowly rolled out in favour of PayFees.
The closed RFC PR on the xcm-format repository, before XCM RFCs got moved to fellowship RFCs: https://github.com/polkadot-fellows/xcm-format/pull/53.
None
This proposal would greatly benefit from an improved asset trapping system.
CustomAssetClaimer is also related, as it directly improves the ergonomics of this proposal.
LeftoverAssetsDestination execution hint would also similarly improve the ergonomics.
The SetFeesMode instruction and the fees_mode register allow for the existence of JIT withdrawal. JIT withdrawal complicates the fee mechanism and leads to bugs and unexpected behaviour. The proposal is to remove said functionality. Another effort to simplify fee handling in XCM.
SetFeesMode
fees_mode
The JIT withdrawal mechanism creates bugs such as not being able to get fees when all assets are put into holding and none left in the origin location. This is a confusing behavior, since there are funds for fees, just not where the XCVM wants them. The XCVM should have only one entrypoint to fee payment, the holding register. That way there is also less surface for bugs.
The SetFeesMode instruction will be removed. The Fees Mode register will be removed.
Fees Mode
Users will have to make sure to put enough assets in WithdrawAsset when previously some things might have been charged directly from their accounts. This leads to a more predictable behaviour though so it will only be a drawback for the minority of users.
WithdrawAsset
Implementations and benchmarking must change for most existing pallet calls that send XCMs to other locations.
Performance will be improved since unnecessary checks will be avoided.
JIT withdrawal was a way of side-stepping the regular flow of XCM programs. @@ -1338,11 +1247,11 @@ the original intended behaviour, which may result in more implementation work. -
The previous RFC PR on the xcm-format repo, before XCM RFCs were moved to fellowship RFCs: https://github.com/polkadot-fellows/xcm-format/pull/57.
The new generic fees mechanism is related to this proposal and further stimulates it as the JIT withdraw fees mechanism will become useless anyway.
A previous XCM RFC (https://github.com/polkadot-fellows/xcm-format/pull/37) introduced a SetAssetClaimer instruction. This idea of instructing the XCVM to change some implementation-specific behavior is useful. In order to generalize this mechanism, this RFC introduces a new instruction SetHints and makes the SetAssetClaimer be just one of many possible execution hints.
SetAssetClaimer
SetHints
There is a need for specifying how certain implementation-specific things should behave. Things like who can claim the assets or what can be done instead of trapping assets. Another idea for a hint:
AssetForFees
LeftoverAssetsDestination
A new instruction, SetHints, will be added. This instruction will take a single parameter of type Hint, an enumeration. The first variant for this enum is AssetClaimer, which allows to specify a location that should be able to claim trapped assets. @@ -1415,14 +1324,14 @@ enum Hint { type NumVariants = /* Number of variants of the `Hint` enum */; } -
Hint
AssetClaimer
The SetHints instruction might be hard to benchmark, since we should look into the actual hints being set to know how much weight to attribute to it.
Hints are specified on a per-message basis, so they have to be specified at the beginning of a message. If they were to be specified at the end, hints like AssetClaimer would be useless if an error occurs beforehand and assets get trapped before ever reaching the hint.
The instruction takes a bounded vector of hints so as to not force barriers to allow an arbitrary number of SetHint instructions.
SetHint
The SetHints instruction provides a better integration with barriers. @@ -1431,11 +1340,11 @@ Also, this instruction would make it simpler to write XCM programs. You only need to specify the hints you want in one single instruction at the top of your program.
The previous RFC PR in the xcm-format repository before XCM RFCs moved to fellowship RFCs: https://github.com/polkadot-fellows/xcm-format/pull/59.
This RFC proposes a solution to replicate an existing pure proxy from one chain to others. The aim is to address the current limitations where pure proxy accounts, which are keyless, cannot have their proxy relationships recreated on different chains. This leads to issues where funds or permissions transferred to the same keyless account address on chains other than its origin chain become inaccessible.
A pure proxy is a new account created by a primary account. The primary account is set as a proxy for the pure proxy account, managing it. Pure proxies are keyless and non-reproducible, meaning they lack a private key and have an address derived from a preimage determined by on-chain logic. More on pure proxies can be found here.
For the purpose of this document, we define a keyless account as a "pure account", the controlling account as a "proxy account", and the entire relationship as a "pure proxy".
The relationship between a pure account (e.g., account ID: pure1) and its proxy (e.g., account ID: alice) is stored on-chain (e.g., parachain A) and currently cannot be replicated to another chain (e.g., parachain B). Because the account pure1 is keyless and its proxy relationship with alice is not replicable from the parachain A to the parachain B, alice does not control the pure1 account on the parachain B.
pure1
alice
A
B
Given that these mistakes are likely, it is necessary to provide a solution to either prevent them or enable access to a pure account on a target chain.
Runtime Users, Runtime Devs, wallets, cross-chain dApps.
One possible solution is to allow a proxy to create or replicate a pure proxy relationship for the same pure account on a target chain. For example, Alice, as the proxy of the pure1 pure account on parachain A, should be able to set a proxy for the same pure1 account on parachain B.
To minimise security risks, the parachain B should grant the parachain A the least amount of permission necessary for the replication. First, Parachain A claims to Parachain B that the operation is commanded by the pure account, and thus by its proxy, and second, provides proof that the account is keyless.
The replication process will be facilitated by XCM, with the first claim made using the DescendOrigin instruction. The replication call on parachain A would require a signed origin by the pure account and construct an XCM program for parachain B, where it first descends the origin, resulting in the ParachainA/AccountId32(pure1) origin location on the receiving side.
DescendOrigin
ParachainA/AccountId32(pure1)
There are two disadvantages to this approach:
We could eliminate the first disadvantage by allowing only the spawner of the pure proxy to recreate the pure proxies, if they sign the transaction on a remote chain and supply the witness/preimage. Since the preimage of a pure account includes the account ID of the spawner, we can verify that the account signing the transaction is indeed the spawner of the given pure account. However, this approach would grant exclusive rights to the spawner over the pure account, which is not a property of pure proxies at present. This is why it's not an option for us.
As an alternative to requiring clients to provide a witness data, we could label pure accounts on the source chain and trust it on the receiving chain. However, this would require the receiving chain to place greater trust in the source chain. If the source chain is compromised, any type of account on the trusting chain could also be compromised.
A conceptually different solution would be to not implement replication of pure proxies and instead inform users that ownership of a pure proxy on one chain does not imply ownership of the same account on another chain. This solution seems complex, as it would require UIs and clients to adapt to this understanding. Moreover, mistakes would likely remain unavoidable.
Each chain expressly authorize another chain to replicate its pure proxies, accepting the inherent risk of that chain potentially being compromised.
There is a security issue, not introduced by the proposed solution but worth mentioning. The same spawner can create the pure accounts on different chains controlled by the different accounts. This is possible because the current preimage version of the proxy pallet does not include any non-reproducible, chain-specific data, and elements like block numbers and extrinsic indexes can be reproduced with some effort. This issue could be addressed by adding a chain-specific seed into the preimages of pure accounts.
The replication is facilitated by XCM, which adds some additional load to the communication channel. However, since the number of replications is not expected to be large, the impact is minimal.
The proposed solution does not alter any existing interfaces. It does require clients to obtain the witness data which should not be an issue with support of an indexer.
This RFC proposes compressing the state response message during the state syncing process to reduce the amount of data transferred.
State syncing can require downloading several gigabytes of data, particularly for blockchains with large state sizes, such as Astar, which has a state size exceeding 5 GiB (https://github.com/AstarNetwork/Astar/issues/1110). This presents a significant challenge for nodes with slower network connections. Additionally, the current state sync implementation lacks a persistence feature (https://github.com/paritytech/polkadot-sdk/issues/4), meaning any network disruption forces the node to re-download the entire state, making the process even more difficult.
This RFC benefits all projects utilizing the Substrate framework, specifically in improving the efficiency of state syncing.
The largest portion of the state response message consists of either CompactProof or Vec<KeyValueStateEntry>, depending on whether a proof is requested (source):
CompactProof
Vec<KeyValueStateEntry>
None identified.
The code changes required for this RFC are straightforward: compress the state response on the sender side and decompress it on the receiver side. Existing sync tests should ensure functionality remains intact.
This RFC optimizes network bandwidth usage during state syncing, particularly for blockchains with gigabyte-sized states, while introducing negligible CPU overhead for compression and decompression. For example, compressing the state response during a recent Polkadot warp sync (around height #22076653) reduces the data transferred from 530,310,121 bytes to 352,583,455 bytes — a 33% reduction, saving approximately 169 MiB of data.
Performance data is based on this patch, with logs available here.
No compatibility issues identified.
This RFC proposes a new host function, secp256r1_ecdsa_verify_prehashed, for verifying NIST-P256 signatures. The function takes as input the message hash, r and s components of the signature, and the x and y coordinates of the public key. By providing this function, runtime authors can leverage a more efficient verification mechanism for "secp256r1" elliptic curve signatures, reducing computational costs and improving overall performance.
secp256r1_ecdsa_verify_prehashed
NIST-P256
r
s
x
y
“secp256r1” elliptic curve is a standardized curve by NIST which has the same calculations by different input parameters with “secp256k1” elliptic curve. The cost of combined attacks and the security conditions are almost the same for both curves. Adding a host function can provide signature verifications using the “secp256r1” elliptic curve in the runtime and multi-faceted benefits can occur. One important factor is that this curve is widely used and supported in many modern devices such as Apple’s Secure Enclave, Webauthn, Android Keychain which proves the user adoption. Additionally, the introduction of this host function could enable valuable features in the account abstraction which allows more efficient and flexible management of accounts by transaction signs in mobile devices. Most of the modern devices and applications rely on the “secp256r1” elliptic curve. The addition of this host function enables a more efficient verification of device native transaction signing mechanisms. For example:
This RFC proposes a new host function for runtime authors to leverage a more efficient verification mechanism for "secp256r1" elliptic curve signatures.
Proposed host function signature:
#![allow(unused)] @@ -1694,23 +1603,114 @@ Most of the modern devices and applications rely on the “secp256r1” elliptic ) -> bool; }
The host function MUST return true if the signature is valid or false otherwise.
true
false
The changes are not directly affecting the protocol security, parachains are not enforced to use the host function.
The host function proposed in this RFC allows parachain runtime developers to use a more efficient verification mechanism for "secp256r1" elliptic curve signatures.
Parachain teams will need to include this host function to upgrade.
The primary stakeholders of this RFC are: +– DOT token holders – as this affects the protocol's treasury +– Entities wishing to submit a referendum on these tracks – as this affects the referendum's timeline +– Projects with governance app integrations – see Performance, Ergonomics and Compatibility section below