▁Comput ing . ▁ 1 9 9 8 ▁Mar ; 2 ( 2 ): 6 0 - 4 . ▁ ▁Pat ents ▁ ▁Pat ents ▁that ▁are ▁c ited ▁more ▁than ▁one ▁hundred ▁times : ▁ ▁Gu pta ▁A , ▁Ferr is ▁C , ▁Abd eln ur ▁A , ▁invent ors ; ▁Sun ▁Mic ros ystem s ▁Inc , ▁ass igne e . ▁Method ▁and ▁appar atus ▁for ▁authentic ating ▁users . ▁United ▁States ▁pat ent ▁US ▁ 6 , 2 2 6 , 7 5 2 . ▁ 2 0 0 1 ▁May ▁ 1 . ▁ ▁Wood ▁D L , ▁W esch ler ▁P , ▁N orton ▁D , ▁Ferr is ▁C , ▁Wilson ▁Y , ▁So ley ▁W R , ▁invent ors ; ▁Sun ▁Mic ros ystem s ▁Inc , ▁ass igne e . ▁Log - on ▁service ▁providing ▁cred ential ▁level ▁change ▁without ▁loss ▁of ▁session ▁continu ity . ▁United ▁States ▁pat ent ▁US ▁ 6 , 6 0 9 , 1 9 8 . ▁ 2 0 0 3 ▁Aug ▁ 1 9 . ▁ ▁Wood ▁D L , ▁N orton ▁D , ▁W esch ler ▁P , ▁Ferr is ▁C , ▁Wilson ▁Y , ▁invent ors ; ▁Sun ▁Mic ros ystem s ▁Inc , ▁ass igne e . ▁Single ▁sign - on ▁framework ▁with ▁trust - level ▁mapping ▁to ▁authentication ▁requirements . ▁United ▁States ▁pat ent ▁US ▁ 6 , 8 9 2 , 3 0 7 . ▁ 2 0 0 5 ▁May ▁ 1 0