The ICON Foundation announced it was working on ICON Bridge earlier this month.

The so-called “early iteration of BTP” aims to overcome an unforeseen challenge in BTP’s development, namely, unsustainably high gas consumption fees incurred when executing the BTP Message Verifier Contract (BMV).

Anyway, we asked ICON strategist Scott Smiley some questions about ICON Bridge to get a better understanding of this soon-to-be new addition to the ICON ecosystem.

BTP, minus the BMV

Is ICON Bridge a “light” version of BTP?

You could say that, says Scott, who explains the the specific difference with BTP proper is that ICON Bridge “does not utilize the BMV component of BTP, which requires more development time.”

It’s an interim solution,” he says.

The BMV is a “a live, miniature copy of the source blockchain that exists on the destination blockchain.” It’s what allows smart contracts to verify cross-chain transactions rather than trusted validators, and they require constant updating to mirror the original chain.

Unfortunately, keeping the BMV contracts updated has proven prohibitively expensive in terms of gas fees.

Nevertheless, ICON Bridge and BTP will offer the exact same planned functions.

From a UX standpoint, there is no difference between ICON Bridge and the first planned version of BTP,” says Scott. “Both support wrapping/unwrapping of tokens between networks.”

Scott says from a technical standpoint, he would assume ICON Bridge is “fairly similar” to other bridge solutions like the Polygon and Avalanche bridges, but better for ICON. He explains, “The only major difference in terms of how it helps the ICON community is that ICON Bridge will generate fees that support the ICON ecosystem.”

So, how is this gas fee problem going?

When asked how efforts to resolve the BMV gas fee problem were going, Scott pointed me to a Twitter thread of his about a recent meeting of DApp and BTP developers.

The meeting focused on research and architecture considerations for the short/long term of BTP.

Basically, there are short term, mid-term and long-term solutions.

  • Short term: “The fastest path forward to a product release is to simply remove the BMV. This solves the aforementioned gas problem and also the hard-fork requirement, but sacrifices the trustless nature of BTP. The Relay becomes trusted.” (This is essentially what ICON Bridge does)
  • Mid-term: “There are other ways to lower the cost of the BMV blockUpdates through more development. The leading plan is to only verify signatures on the final block of a blockUpdate rather than every block. The NEAR BTP integration team is implementing/testing this.”
  • Long-term: “ICON controls its own chain so can optimize for BTP. For updating ICON-based BMVs, the leading plan is to whitelist these contracts at the core level and simply not charge network fees (or something minimal) for blockUpdates. This also builds a moat for BTP. For non-ICON BMVs, core devs are planning “BTP Blocks”. P-Reps would only produce BTP blocks when a BTP message is being sent, meaning there would no longer be a need to constantly update non-ICON BMVs with blocks unrelated to BTP.”

According to another ICON insider, ICON Bridge will feature integration with Binance Smart Chain at first, followed soon after by Moonbeam. Other integrations will follow later.

Unlike BTP, ICON Bridge will not force other chains to hard fork to implement the bridge, which could induce other chains to join BTP.

Nevertheless, as the ICON Foundation has said, ICON Bridge is an interim solution, with emphasis on the “interim.” As for what will happen to it after BTP launches in earnest, Scott said, “I would expect it to migrate to BTP.”

The ICON team is aiming to releases the first integration of ICON Bridge with BSC at the end of March.