IBM is considering adopting the underlying technology behind bitcoin, known as the "blockchain," to create a digital cash and payment system for major currencies.The objective is to allow people to transfer cash or make payments instantaneously using this technology without a bank or clearing party involved, saving on transaction costs. The transactions wouldbe in an open ledger of a specific country's currency such as the dollar or euro.The blockchain - a ledger, or list, of all of a digital currency's transactions is viewed as bitcoin's main technological innovation, allowing users to make payments anonymously, instantly, and without government regulation.Rather than stored on a separate server and controlled by an individual, company, or bank, the ledger is open and accessible to all participants in the bitcoin network.The proposed digital currency system would work in a similar way.