Bitcoin, halal or haram?

The Masjid Ramadan mosque located in Hackney in East London, now allows its faithful to pay alms in bitcoins or ethers. Donations collected will be used to restore the building. Regarded as halal by some, including the Indonesian scholar Muhammad Abu-Aaka, author of a study on the subject , Bitcoin is rejected by others like the great Mufti of Egypt who said that bitcoin was "unacceptable" , because " it encroaches on the authority of the State in the preservation of the currencies" .