A small group of Bitcoin and Lightning developers is working on a new class of “sighash flags,” with names like SIGHASH_NOINPUT (“Noinput”), SIGHASH_ANYPREVOUT (“Anyprevout”) and SIGHASH_ANYPREVOUTANYSCRIPT (“Anyprevoutanyscript”). One or several of these could see deployment as a soft fork protocol upgrade in the not-too-distant future to help streamline the Lightning user experience in two big ways.