US2008179399A1
|
|
Method of confirming electoral vote
|
US2006202468A1
|
|
Security document having integrated copy-void and validation security features
|
US7625613B2
|
|
Copy-resistant security paper
|
US2003080550A1
|
|
Security envelope detectable for foreign substances
|
US6692030B1
|
|
Security document with nano-pattern
|
EP1068079A1
|
|
Chemically and relief encoded security papers
|
US6396927B1
|
|
Variable density verification
|
US6082775A
|
|
Chemically encoded security papers
|
US6106021A
|
|
Security papers with unique relief pattern
|
US5762378A
|
|
Tamper resistant validation marks
|
US5873604A
|
|
Document security system having thermo-activated pantograph and validation mark
|
US5772248A
|
|
Document with tamper and counterfeit resistant relief markings
|
US5704651A
|
|
Counterfeit resistant documents and methods
|
US5695220A
|
|
Visual validation mark for bank checks and other security documents
|