This note does not seek to examine the various juristic definitions of māl. Rather, it argues that merely describing cryptocurrencies as digital numbers or ledger entries does not seem sufficient to exclude them from the category of māl. The same description applies to modern banking, electronic money, and numerous forms of intangible financial rights. In fact, what we call fiat currencies—such as the Pakistani Rupee or the US Dollar—have themselves largely become ledger entries. The balances held in bank accounts (including those of Islamic banks) are, in reality, digital records.
Islamic Economics Project 