As far as I understand it, the address is a hash of the public key. Please correct me if I'm wrong by the way!
This means, as soon as the actual public key is in the wild (typically after a transaction has been made _from_ an address, not just to it) you could calculate any other address with different prefixes, like NMC, testnetBTC and so on.
Namecoin is not used for messages as far as I know by the way, you might confuse this with Bitmessage maybe?
Not yet. But this is a possible user case.
http://dot-bit.org/Use_cases Of course it wouldn't have sense using in an identical way like Bitmessage.
But it could have sense to use for information kept forever in the namecoin blockchain, for example to publish a virtual identity associated to a bitcoin address.(email, IRC, messenger, but also other data what the owner of the address wish)
For example:
1.
- Somebody posts an interesting business idea in a forum and sign it with a namecoin address. He doesn't need to post other contact details.
- You are interested in it and want to contact him. In his namecoin address you can locate additional messages or contact details from him and you can also find out his donation receiving address.
2.
- Somebody is sending to you a higher amount of bitcoins. You know only his bitcoin address.
- If you can transform the bitcoin address to his namecoin address you could find additional informations/messages/contact address and you could thank him.
3.
- A charity organization is posting his donation receiving bitcoin address.
- On the corresponding namecoin address you could find contact address/email and if it is the registration number of the organization.
