Lehigh University

•  HIP2005 Home

•  Call for Participation

•  Organization

•  Author Instructions

•  Program

•  Participants

•  Presentations

•  Local Arrangements

•  Registration

•  PatRec Lab

Microsoft Research
Supported by
Microsoft Research

Endorsed by the International Association for Pattern Recogntion

LNCS logo
HIP2005 proceedings is published by Springer as LNCS Volume 3517

PRR logo
Lehigh Pattern
Research Lab

We wish to thank all attendees for making
the HIP2005 workshop a great success!
Henry and Dan

Second International Workshop on


May 19-20, 2005
Lehigh University
Bethlehem, PA  18015 USA

E-commerce services are suffering abuse by programs (bots, spiders, etc.) which masquerade as legitimate human users.  Efforts to defend against such attacks have, over the last few years, stimulated the investigation of a new family of security protocols -- "Human Interactive Proofs" (HIPs) -- which allow a person to authenticate herself as a member of a given group: e.g. as human (vs. machine), as herself (vs. anyone else), as an adult (vs. a child), etc.  The vast majority of commercial uses of HIPs today are CAPTCHAs -- "Completely Automatic Public Turing tests to tell Computers and Humans Apart" -- which exploit the gap in ability between humans and machine vision systems in reading images of text.  HIP challenges can also be non-graphical, e.g., requiring recognition of speech, solving puzzles, etc.

Since the First Workshop on Human Interactive Proofs in January 2002, the use of CAPTCHAs has risen rapidly worldwide and awareness of HIPs has spread through many articles in the scientific and general press.  UC Berkeley has broken the Yahoo/CMU EZ-Gimpy CAPTCHA.  Microsoft Research, PARC, and Lehigh University have developed new generations of reading-based CAPTCHAs.  CAPTCHAs have emerged as a front-line defense against spam.  Many new applications are emerging.

This workshop will bring together researchers, engineers, and users of HIPs and CAPTCHAs to review the state of the art, discuss recent technical and commercial progress, identify pressing technical and business challenges, and to plan next steps for the field.

Workshop Chairs:
Henry BAIRD   and   Daniel LOPRESTI
Computer Science & Engineering, Lehigh University

Email inquiries*:  

Workshop URL:

     HIP2005 Workshop, CSE Dept, Lehigh University,
     19 Memorial Dr West, Bethlehem, PA  18015 USA
     Tel. +1-610-758-6671   FAX +1-610-758-4096

* The email addresses on this webpage are expressed in image format as simple CAPTCHAs to make it more difficult for "bots" to harvest them for spam purposes.  The HIP2005 logo at the top of the page is an example of "ScatterType" developed by Henry Baird and Terry Riopka.


© 2004 P.C. Rossin College of Engineering & Applied Science
Computer Science & Engineering, Packard Laboratory, Lehigh University, Bethlehem PA 18015