Proposes two novel cash-based micropayment schemes based on a new technique referred to as the double-locked hash chain technique. Both schemes support the divisibility and transferability of digital coins in a simpler way compared to the existing solutions. The basic scheme allows full or partial use of a coin chain in a transaction; if only part of a coin chain has been used with one vendor, the rest of the chain can be used, for instance in a subsequent transaction with another vendor. The modified scheme extends this to multiple chains, making the scheme particularly suitable for a large number of micropayment transactions.