Investing.com - Amid the uncertainty of the cryptocurrency slump, comes the certainty of blockchain technology.The launch of Banco Santander (MC:SAN)'s Ripple-based international money transfer payment service shows both the commercial viability and transformational power of blockchain distributed ledger technology.The service, called Santander One Pay FX, facilitates same-day currency exchange for retail customers in four countries --Spain, the UK, Brazil and Poland. The simultaneous, multiple country launch is the first of its kind. The smartphone app service will be expanded to other countries in the coming months. A payment app developed by Ripple and a consortium of Japanese banks is scheduled to launch in the fall.Ripple is also partnering with a number of other financial firms, including American Express (NYSE:AXP) and UBS.