Looking for a safe alternative to bitcoin among altcoins? That's foolish, to say the least. No altcoin can give you as much security as bitcoin. Not a single one. All altcoins are centralized because they have developers, they have core investors who invested in the cryptocurrency in the earliest stages of development. These people often control the entire ecosystem and the circulating supply of coins. What kind of security and decentralization are you talking about? You are trying to look for unicorns and phoenixes among cryptocurrencies. They don't exist.