Presenting CCBN


A decentralized way to prevent double-spends from 51% attacks.

Originally posted here alongside draft whitepaper with full details.

A brief overview of CCBN:

What is Notarization, and how does it work?

BTG blocks are Notarized to well-known public blockchains which serve as our “Notarychains.”

Notarizations contain complete BTG block headers with the solution hashes (so they cannot be easily faked.)

Notarizations gain Weight based on their depth in the Notarychain. Those made earlier gain Weight faster than those made later.

When are Notarizations used?

When a competing chain of blocks (a fork) appears, BTG nodes with CCBN do not switch to the longer chain immediately.

Instead, they check the Notarychains to calculate Weight and will only switch to a longer chain that also has more Weight.

If a “natural” fork occurs and all blocks are Notarized, CCBN has no effect. No change to normal PoW (Nakamoto Consensus.)

Secret Mining Attackers are faced with a dilemma:

If a Secret Miner Notarizes blocks, they become public!

Key parties (like Exchanges) can see the Notarizations and will not confirm deposits.

But if a Secret Miner does not Notarize

When they later publish their Secret chain, nodes refuse it because of low Weight, preventing the attack.

Either the first spend is refused by the Exchange, or the second spend is refused by the chain.

Either way, a Double-Spend fails!

It’s a soft fork!

CCBN is essentially a backup Consensus method, used only to arbitrate a chain split in favor of the honest chain.

Simulations show that notarizing to well-selected Notarychains provides > 99% protection against attacks

Fully Decentralized:
No masternodes, notarynodes, federations, consortia, or privileged parties.

Originally posted here alongside draft whitepaper with full details.


The thing about this line is that it’s 99% safety even in the face of a massive attack when an exchange is only requiring 6 confirmations. From the whitepaper: