account.NewAccount weak entropy

[Gustav-Simonsson]

account.NewAccount does not use a cryptographically secure pseudorandom number generator. This makes it possible to derive arbitrary keys generated by other users by brute forcing the randomSeckey function with all values returned from time.UnixNano in some time interval.

Please change the use of math.rand to crypto.rand. Consider using the go-ethereum accounts or keystore packages directly as they have seen extensive auditing and been used to generate keys used in live blockchain networks for a few years.

[flybikeGx]

Thx for your suggestions and further features of our key-pairs and account system will be publish in next version.