Shadders first explained the entire issue surrounding OP_RETURN in a detailed blog post that is definitely worth reading. BitBoss was paying attention and announced in its own post on Medium that it had taken the programming expert’s viewpoints into consideration, making the appropriate changes to its offerings to tighten up applications and prepare for BSV’s Genesis upgrade, scheduled for next February.
Keyring has been updated to support the new OP_FALSE OP_RETURN script type https://t.co/ts0lT4R5P9
— bitbossio (@bitbossio) September 26, 2019
Bitboss explains, “This change will ensure that all apps being developed with Keyring will maintain consistent behavior both now and after the Bitcoin SV Genesis upgrade. Instead of starting a script with OP_RETURN, it should start with OP_FALSE OP_RETURN. A locking script that contains this will always fail when it hits this sequence of op codes both now and after the Genesis upgrade, which is the proper, secure behavior.”
This is an important update, as the original use of OP_RETURN, combined with the OP_SEPARATOR field, was such that there was a bug that could have allowed coins to be spent without going through the proper verification procedures. The issue dates back to the original Bitcoin code and had been patched by Satoshi, but the patch was nothing more than a temporary band-aid that didn’t completely resolve the issue. Shadders’ solution helped to close the loophole completely and support for OP_FALSE OP_RETURN was included when Bitcoin SV v0.2.1 was rolled out in July.