At first sight Nidaba is very similar to Namecoin. To register a pair of name and key you need to spend internal currency. To resolve the disputes about the names Nidaba suggests to use a penny auction. The other Nidaba's distinguished properties are:

• scalabilty (miners don't need to store the whole blockchain)
• resistance to the tragedy of the commons (mining never will depends on the transaction fee only)
• stable price for registration (price is bound to an average miner's hash rate, if the rate goes up the price follows)