Согласно моим поискам, самое первое упоминание термина "cryptocurrency" на этом форуме было 18 марта 2010 года в этом топике -
New Bitcoin Users - Read This ! (Bitcoin Preservation).
Welcome to the Bitcoin Forum and to Satoshi's Bitcoin Project !
You can introduce yourself and ask questions here if you want to.
Please remember that there will only ever be 21,000,000 bitcoins created !
If you decide that the Bitcoin P2P Cryptocurrency is not for you and you have generated bitcoins. Please try to send / donate them to another Bitcoin user before you abandon the project and uninstall the software application.
You can send these donations to NewLibertyStandard or BitcoinFX (myself) or to any other bitcoin address or bitcoin IP which is shown on this forum. Also, try to confirm that the address is still valid and in use.
Thanks.
Regards,
BitcoinFX. ( A fellow Bitcoin user and enthusiast )
Не претендую на истину в последней инстанции, как говорится. Может кто-то найдёт более раннее упоминание.