There are dozens of different wallets on the App Sore and Google Play, and their developers all claim they have created the best wallet. And every product has its pros and cons. Let’s define some important properties of a true cryptocurrency wallet.

1. A wallet should be lightweight and mobile.

Paper wallets, hardware wallets — those are good for long term storage only. Most people would use cryptocurrency on a day-to-day basis to receive money and pay the bills.

2. It should provide a real control over user’s funds, not an imaginary one.

There must be the full access to private keys, they must be stored securely, and connection to the blockchain network must not involve any intermediate servers or schemes that can potentially block access to transaction broadcasting or balance retrieval. The most robust solution is to use the Simplified Payment Verification[1] protocol that was initially described in ‘Bitcoin — P2P Electronic Cash System’ white paper and allows light clients to be full-fledged users of the network without a middleman[2]. Besides direct connection to ordinary networks nodes there are some other solutions, such as connection through publicly available Electrum servers or Insight blockchain explorers.

3. It should be private.

The Bitcoin’s blockchain is as transparent as a glass. During the time when ‘the big brother is watching you’ we need a special privacy for our transactions. There are specialized opaque blockchains such as Monero or Zcash, yet they are on the dawn of their existence, and mobile wallets are yet to come (if we do not count surrogate products that neutralize all the privacy).