A valid digital signature gives a recipient reason to believe that the message was created by a known sender (authentication), that the sender cannot deny having sent the message (non-repudiation), and that the message was not altered in transit (integrity).
Load index is an assigned number that corresponds with the load-carrying capacity of a tire. Most passenger car tire load indexes range from 75 to 100, but a few carry more. You'll also find the maximum load elsewhere on the tire sidewall, both in lbs and kg.
Standard load P-metric will not show a load range but rather a load index like a passenger tire. Extra load P-Metric will be identified with an XL, as in P235/75R15XL. Light truck (LT) and flotation tires have their load range listed with a letter, as in LT235/85R16/E or 31x10.50R15/C.