… a unique hash (e.g. MD5, SHA256, etc.) of the given URL. The hash can then be encoded for display. This encoding could be base36 ([a-z ,0–9]) or base62 ([A-Z, a-z, 0–9]). If we add +
and /
, we can use Base64 encoding. A reasonable question would be, “What should be the length of the short key? 6, 8, or 10 characters…