[notahacker]

As long as the currency's token is unique and scarce and accepted as equivalent to cash by people that have goods to deliver. Many things are unique, scarce and entirely worthless.

If the purpose is to allow Iranians to circumvent restrictions on international trade, then you encounter the problem of not many people wanting to swap their goods or dollars for crypto-rial. (If the purpose is to allow people to make payments within the Iranian banking system in accordance with Iranian law, the crypto layer is redundant)