// other key types are available, only difference is the prefix
key, _ := signkey.NewKey(signkey.UserKeyPrefix)

// serialize the public key and secret
// you need to keep the secret...secret!
pubkeyStr, _ := key.PublicKey()
secretStr, _ := key.Secret()

// deserialize to a new key instance using the secret
// you can sign AND verify data
key2, _ := signkey.FromSecret(secretStr)
data := []byte("howdy partner")
sig, _ := key2.Sign(data)
err := key2.Verify(data, sig)

// now imagine your friend knows your public key.
// we pass sig and data to your friend...

// deserialize to a new key using the public key.
// this new key can only do verification.
key3, _ := signkey.FromPublicKey(pubkeyStr)
err3 := key3.Verify(data, sig)
if signkey.IsInvalidSignature(err3) {
    panic("bad signature!")
}

// now your friend is sure that `data` came from you.

var rawSecret [signkey.SecretSize]byte
_, err := io.ReadFull(rand.Reader, rawSecret[:])
key, _ := signkey.FromRawSecret(UserKeyPrefix, rawSecret)