SmartTrust  
   Secure transactions and exchange of information via the mobile phone with PKI security.
   http://www.sonera.fi/smarttrust/

Diversinet  
   Passport Certificate Server Security software for wireless e-commerce applications.
   http://www.diversinet.com/

iD2  
   PKI, public key infrastructure, smart cards.
   http://www.smarttrust.com/

Attacks against the WAP WTLS Protocol  
   Article by Markku-Juhani Saarinen.
   http://www.jyu.fi/~mjos/wtls.pdf

mi4e  
   Develops mobile internet for ecommerce infrastructure software.
   http://www.mi4e.com

NTRU Cryptosystems  
   Delivers public key cryptography solutions to secure electronic media and wireless communications and content on mobile devices such as the Palm Pilot, or in any constrained environment.
   http://www.ntru.com

WTLS  
   An Introduction to WAP Security at the Network Protocol Layer by Philip Mikal
   http://mikal.org/interests/articles/article0003.jsp

DallasCon  
   Wireless security conference presents both annual information security conferences as well as security training seminars (such as WAP security) held throughout the year. Held in Dallas, Texas.
   http://www.dallascon.com/

Mi4e proposes to fix WAP security hole  
   describes MI4E's IIS webserver module which can allow IIS webservers to interact directly with WAP clients.
   http://www.vnunet.com/News/1112381

WAP Security Introduction  
   An outline of WAP security issues and concerns, particularly addressing the use of WAP gateways.
   http://www.vbxml.com/wap/articles/wap_security/default.asp

WAP security - Frequently asked questions  
   WAP security frequently asked questions regarding sessions, cookies, user authentification and SSL/WTLS over WAP protocol
   http://www.123wapinfo.com/faqs/security/

WTLS-webopedia definition  
   A concise, basic definition of WAP Transactional Layer Security
   http://www.webopedia.com/TERM/W/WTLS.html

Columbitech Security White Papers  
   White papers about WAP security and the WTLS protocol.
   http://www.columbitech.com/Products/white_prod.asp