* {{cite book | last=Tilborg | first=Henk C.A. van | last2=Jajodia | first2=Sushil | title=Encyclopedia of Cryptography and Security | publisher=Springer Science & Business Media | publication-place=New York, NY | date=2011-09-06 | isbn=978-1-4419-5905-8}}
<ref name="u072">{{cite book | last=Tilborg | first=Henk C.A. van | last2=Jajodia | first2=Sushil | title=Encyclopedia of Cryptography and Security | publisher=Springer Science & Business Media | publication-place=New York, NY | date=2011-09-06 | isbn=978-1-4419-5905-8 | page=}}</ref>