Do not store decrypted private keys

[hrobeers]

https://github.com/3s3s/multicoins.org/blob/master/server_side/app.js#L49

DecodeWallet stores the decrypted private keys in localstorage.
It is safer to store the decrypted private keys in memory only.

Some reasons:

• If the user closes the browser tab and forgets to encrypt, the wallet stays decrypted, which is a security risk.
• Localstorage also writes to disk, even if wallets are encrypted consistently, private keys can still be retrieved by attackers.

[3s3s]

Not sure this is such a necessary feature. Most of clients are store decrypted private keys in local drive (wallet.dat). But I will think about the possible implementation this. Thank you.

[hrobeers]

Yes you are correct. If it doesn't fit your wallet, no worries.
It's just something that I'd find important, but like you say most users don't really care.
So if you think it would reduce adoption, feel free to ignore.