Tensions have arisen in the last few days following the release of a video showing how easy it is to double spend bitcoin in over 200 stores in Australia using the TravelbyBit solution.
— Hayden Otto (@haydenotto_) December 18, 2019
The problem originates from the fact that the RBF (Replace-by-Fee) protocol is used to replace one transaction with another.
To do so, it uses a different fee to change the priority: the system has been highly criticised by several people who use bitcoin as a payment method.
We processed over 100,000 transactions with amounts from $5-2000/transaction with no double spends. Over $25m in sales and the first time we got a double spend attack was after RBF was introduced. #justsaying
— Vinny Lingham (@VinnyLingham) October 3, 2018
Since the video was released, TravelbyBit has removed this payment method from POS (Points of Sale). As stated by CEO Caleb Yeoh himself:
“We will be dropping both Bitcoin and Bitcoin Cash from the POS (Point of Sale). If we see more of this taking place we would have to drop Bitcoin and Bitcoin Cash on-chain transactions on all our merchants across Australia”.
“The truth is both Bitcoin and Bitcoin Cash and many other blockchains are not suitable for retail point of sale transactions. There are trade-offs between user experience vs security.”
In addition, it is worth mentioning that support for Lightning Network (LN) will continue to be provided and thus bitcoin payments can still be used. This is certainly a serious setback for the company.
The decision has also affected the possibility of making payments with Bitcoin Cash (BCH), although it is not clear why, since BCH has removed the RBF protocol and SegWit (Segregated Witness) and therefore the same dangers would not be present for BCH payments. Whereas Bitcoin Satoshi Vision (BSV) has not been disabled.