* <code>false<code>, if the seed exists but is not authenticated
* <code>null</code>, if the seed does not exist at all
* @throws SQLException in case of an database error
*/
public Boolean verifySeed(String username, String seed) throws SQLException {
DBTransaction transaction = TransactionPool.get().beginWork();
try {
return verifySeed(transaction, username, seed);
} finally {
TransactionPool.get().commit(transaction);
}