user5363: If I'm reading the website right, it's saying that both Wallet passphrase and name should be kept private.
I now have a conundrum of which name to choose. Should I put my default username (public, well-known by those who know me), or should I put something that is hard to guess (like a password)?
How are the wallet name and passphrase even used in the system? Will someone give me his Wallet name, so I will be able to transfer money to him?

user2306: As a rule of thumb, don't give an attacker any more information than you have to. I would say that you should use your normal username; put the effort of remembering an odd username into remembering a better password.

How are the wallet name and passphrase even used in the system? Will someone give me his Wallet name, so I will be able to transfer money to him?

Nope. The username + password is used to look up a wallet file from something called a 'blob vault'. That blob vault contains your private key and your addressbook.

5363: <p>If I'm reading the website right, it's saying that both Wallet passphrase <em>and</em> name should be kept private.</p>

<p>I now have a conundrum of which name to choose. Should I put my default username (public, well-known by those who know me), or should I put something that is hard to guess (like a password)?</p>

<p>How are the wallet name and passphrase even used in the system? Will someone give me his Wallet name, so I will be able to transfer money to him?</p>
 2306: <p>As a rule of thumb, don't give an attacker any more information than you have to. I would say that you should use your normal username; put the effort of remembering an odd username into remembering a better password.</p>

<blockquote>
  <p>How are the wallet name and passphrase even used in the system? Will someone give me his Wallet name, so I will be able to transfer money to him?</p>
</blockquote>

<p>Nope. The username + password is used to look up a wallet file from something called a <a href="https://github.com/rippleFoundation/Blob-Vault" rel="nofollow">'blob vault'</a>. That blob vault contains your private key and your addressbook.</p>
