Question about Curve25519

Hey,

Didn't see a list for Curve25519 so I tried this one.  I'm basically
curious whether it's possible to leverage Curve25519 to provide simple
signing such that anyone can verify the signature.  I came up with the
following probably incredibly retarded code to generate a signature
key, but I just know it has to be wrong:

    unsigned char a_prv[32];
    unsigned char a_pub[32] = {0};
    unsigned char basepoint[32] = {9};
    unsigned char null_pubkey[32] = {0};
    unsigned char a_sigkey[32] = {0};
    unsigned char b_sigkey[32] = {0};
    
    a_prv[0] &= 248; a_prv[31] &= 127; a_prv[31] |= 64;

    // generate A's public key
    curve25519(a_pub, a_prv, basepoint);
    // generate a generic "null" pubkey from basepoint
    curve25519(null_pubkey, basepoint, basepoint);
    
    curve25519(a_sigkey, a_prv, null_pubkey);
    // A would use a_sigkey to encrypt a hash from this
    
    curve25519(b_sigkey, basepoint, a_pub);
    // B, knowing basepoint and A's pubkey can now verify the hash

The idea being that using basepoint for both public and private keys
generates a key everyone can create and use to verify.  But, I'm pretty
niave on this level of cryptography.  Is there an alternative way of
leveraging curve25519 to do publicly verifiable signatures?

I've contemplated the following:

1)  Do the "double basepoint" thing above.  Not sure if this suddenly
breaks A's private key easily.
2)  Generate a "universal public/private key combo" that everyone
knows.  A would then sign using the universal public key, and everyone
would verify the sig using A's public and the universal private key.
3)  Use a third party trusted server to act as intermediary.

Anyway, great library that curve25519.  Love it.

Zed A. Shaw
http://www.zedshaw.com/