I’ve created an open-source, highly-secure wallet at
The purpose of this wallet is to provide cold storage level security with close to web wallet convenience.
The way it works is
- User creates 2 different keys (on 2 different devices, if you want to be extra careful).
- The platform underlying the wallet (TrustedCoin) creates a 2-of-3 multisig P2SH address, where the user owns 2 of the 3 keys.
- When anyone tries to spend coins from this address, TrustedCoin will email and SMS the user with details of the transaction, and give the user 24 hours to cancel before signing and broadcasting it.
So if your computer gets infected with malware, the worst it can do is spam you with spending attempts.
If this should happen — or if TrustedCoin were to disappear — the wallet also allows you to combine both keys and instantly transfer funds to a new address.
I’ll be online for a while to answer any of your questions.
Edit: several comments have pointed out (correctly) that you still have to trust the wallet creator. If you like the idea of the security TrustedCoin provides (i.e., notifying you of transactions and giving you time to cancel), I’d like to suggest that you reach out to your favorite wallet provider, and recommend that they integrate with the TrustedCoin APIs.