▁sets ▁of ▁cardinal ity ▁at ▁most ▁. ▁Appro xim ate ▁min - wise ▁independence ▁diff ers ▁from ▁the ▁property ▁by ▁at ▁most ▁a ▁fixed ▁. ▁ ▁Open ▁source ▁methods ▁ ▁N ils im sa ▁Hash ▁ ▁N ils im sa ▁is ▁a ▁local ity - sens itive ▁has hing ▁algorithm ▁used ▁in ▁anti - sp am ▁efforts . ▁The ▁goal ▁of ▁N ils im sa ▁is ▁to ▁generate ▁a ▁hash ▁dig est ▁of ▁an ▁email ▁message ▁such ▁that ▁the ▁dig ests ▁of ▁two ▁similar ▁messages ▁are ▁similar ▁to ▁each ▁other . ▁ ▁The ▁paper ▁suggests ▁that ▁the ▁N ils im sa ▁satisfies ▁three ▁requirements : ▁▁ ▁The ▁dig est ▁ident ifying ▁each ▁message ▁should ▁not ▁vary ▁significantly ▁for ▁changes ▁that ▁can ▁be ▁produced ▁automatically . ▁ ▁The ▁encoding ▁must ▁be ▁robust ▁against ▁intent ional ▁attacks . ▁ ▁The ▁encoding ▁should ▁support ▁an ▁extremely ▁low ▁risk ▁of ▁false ▁posit ives . ▁ ▁T L SH ▁ ▁T L SH ▁is ▁local ity - sens itive ▁has hing ▁algorithm ▁designed ▁for ▁a ▁range ▁of ▁security ▁and ▁digital ▁for ens ic ▁applications . ▁The ▁goal ▁of ▁T L SH ▁is ▁to ▁generate ▁a ▁hash ▁dig est ▁of ▁document ▁such ▁that ▁if ▁two ▁dig ests ▁have ▁a ▁low ▁distance ▁between ▁them , ▁then ▁it ▁is ▁likely ▁that ▁the ▁messages ▁are ▁similar ▁to ▁each ▁other . ▁ ▁Test ing ▁performed ▁in ▁the ▁paper ▁on ▁a ▁range ▁of ▁file ▁types ▁identified ▁the ▁N ils im sa ▁hash ▁as ▁having ▁a ▁significantly ▁higher ▁false ▁positive ▁rate ▁when ▁compared ▁to ▁other