Yes statistically most of the ransom payment has been in Fiat but we can not say the same about funding, the terrorism situation in Nigeria and Africa at large are heavily funded by the people in the government and I'm sure most of funding are paid via crypto currency, why some are paid through gold and other natural resources.
Although, we are now in 2021 and the year has almost ended, but according to Chainanalysis report last year, less than 1% of crypto transactions are involved in illicit activities. Also, Africa has the lowest share of regional cybercrime value sent. Scam receive most of the illicit value. There is much about Darknet like drugs...
With this report not emphasizing on terrorism, I do not think cryptocurrencies are used for terrorism in Africa or just little are used if compared to fiat. People supply terrorists foods and other things they need will even prefer it in fiat. Although, may Nigeria terrorists will be gradually changing from fiat to cryptocurrencies, but cryptocurrencies like bitcoin can not be used as its blockchain is transparent and available to the public.
For those who want to use E-naira you want to know the charges
1. You are given 90 days free transactions afterward you pay N10 for transactions from N5000 and below, N25 from N5001 - N50,000 and N50 for N50,001 and above, this is insane charged man.
ENaira is naira, I do not see the difference between them both while I will also prefer to make use of naira directly for payment with low charge. Also, CBDCs are not cryptocurrencies, they are just digital currencies not different from the digit fiat used for electronic transactions.