Looks nice – but it is not &#x27;private&#x27;.<p>Using only 6 characters as a &#x27;private&#x27; URL is too small. How long does it take to have a bot that can make 1000 requests per second to download every single URL in your URL space?<p>((alphabet_size^number_url_characters)&#x2F;(request_speed))&#x2F;secs&#x2F;mins&#x2F;hrs = time_in_days<p>((26^6)&#x2F;(1000))&#x2F;60&#x2F;60&#x2F;24 = 3.6 days<p>Reading every single paste in 3.6 days is not private.<p>You want to reduce the probability of a single URL guess colliding with an existing &#x27;private&#x27; URL so that it would take years for a bot to have a decent chance of finding a URL that is already in use.<p>Read up on the probability of hashing collisions and how fast bots can make requests. Make sure it takes a long time to make enough guesses to have a chance at collision.<p>If you don&#x27;t want to do math, just use as many characters as an established company that already has &#x27;private URL sharing&#x27;. ex Dropbox, I think they use ~40 case-sensitive-alphanumeric-characters or something.