For p2sh multisig TXs the order of the public keys affect the hash and there doesn't seem to be an agreed upon way of sorting the public keys.

If there would be a standard (recommended) way of sorting the public keys that would make it easier for services that implement some form of multisig to be compatible with each other without much hassle and making it possible to import keys from one service to another.

I'm not suggesting forcing the order, just setting a standard to recommend, there doesn't seem to be much reason for (new) services to not follow that recommendation.

Ryan from BitPay broad this up before (https://sourceforge.net/p/bitcoin/mailman/message/32092958/) and in bitcore they've implemented lexicographical sorting on the hex of the public key.

In a short search I can't find any other library that has a sorting function, let alone using it by default, so bitcore is currently my only reference.

​Ruben de Vries

​CTO, BlockTrail