do not need "ijtihad" to determine the forbidden or halalof bitcoin? I think we use logic here, bitcoin is the same currency as fiat right? if local currency in your country is used for illegal activities. does fiat become haram? of course not, so same with bitcoin, if bitcoin is used for illegal activities, it does not mean bitcoin is forbidden in islam,
Been a lot of discussion lately in my part of the world (Southeast Asia) regarding this. The convening groups here are quite liberal (if that's one way the outside world describes them) and the same logic is used, for the sake of practical purposes... which is what they always try to do when it comes to Islamic transposing on the financial structure here.
They're leaning heavily towards Bitcoin as simply a means of exchange, much like the rest of progressive Europe. It neither classified Bitcoin as permitted nor forbidden.
BTW, there is an Islamic bank that will use not only Bitcoin but its own digital token and other cryptos on its blockchain project. Malaysian based Hada DBank. They're raising quite a few eyebrows over here...