#6 Referendum proposal: Open HRMP channel between Bifrost and Karura parachain

TL:DR

This is to propose the opening of an HRMP tunnel, in order to support the cross-chain communication between Bifrost and Karura.

Description

There are multiple on-chain proposals including open HRMP cross-chain communication between Bifrost and Karura parachain and List BNC/kUSD pair via Bootstrap on Karura Swap . On-chain proposal will be posted soon.

Summary

HRMP (Horizontally Relay-routed Message Passing) is a stop-gap that precedes XCMP. Semantically, it copies XCMP’s interface. The crucial difference from XCMP is that all the messages are stored in the relay-chain storage. The HRMP will be expected to retire once the XCMP is available.

Opening of HRMP channel between Bifrost and Karura will initially release the cross-chain communication between two parachains:

  • Tokens on both sides can be transferred to each other.
  • Messages can be received on both sides, calling functions by each other.

Proposal

Some more technical parameters from Bifrost side.

Two proposals are required on Karura and Bifrost to establish a bidirectional HRMP channel.
The whole flow will be roughly like:

  1. Initiate requests
    a. Karura’s proposal to request to open Karura to Bifrost HRMP channel
    b. Bifrost’s proposal to request to open Bifrost to Karura HRMP channel
  2. Wait until proposals on step 1 are approved & enacted
  3. Accept requests
    a. Karura’s proposal to accept Bifrost to Karura HRMP channel
    b. Bifrost’s proposal to accept Karura to Bifrost HRMP channel
  4. Wait until proposals on step 3 are approved & enacted
  5. Wait for another session on Kusama for the change to be effective
  6. Cross-chain transfer BNC will be possible at this stage. Other kinds of cross-chain interaction such as transfer of KAR & kUSD will be enabled at later stage via runtime upgrade of Karura & Bifrost.

Initiate open HRMP channel request to Karura (Done)

  • :raising_hand_man: Voting Period: #481,486

  • :rocket: Activate Period: #481,773

  • Encoded call: 0x3c00d0070000e803000000900100

  • Recipient: 2000

  • Proposed max capacity: 1000

  • Proposed max message size: 102400

  • Proposal preimage: 0x4a00010000040a00070010a5d4e808070100ca9a3b00000000005ed0b2000000000004060000ca9a3b00000000383c00d0070000e80300000090010001040101020070617261d1070000000000000000000000000000000000000000000000000000

  • Proposal hash: 0x7ff0ede21f0f7e117fd04ad5798de4d35d9c04e3259afe7887a824e616a43b29

This withdraws 1 KSM to buy transaction fee, execute the call to accept open channel request, and refund remaining KSM to the parachain sovereign account eGJrytyJYDzMGM1uji4Bx5ntw3xF6aifJ7Xvo3mE48cgW5N

4 Likes

Good to hear

Its great news

Update progress, #6 referendum proposal is submitted!