David joined Bessemer Venture Partners in 1992. David has since made 43 early-stage investments for Bessemer, including 19 that have gone public, and 16 that have been acquired by public companies. David initially focused on communications technology companies like Ciena, P-Com, and PSI-Net, and then internet services such as Keynote, Flycast, Hotjobs and Blue Nile. In 1995 he cofounded Verisign as a Bessemer-funded spinout of RSA, serving as VeriSign's initial Chairman and CFO. His other data security investments have included Counterpane, Cyota, Determina, eEye, Elemental Security, Finjan, ON Technology (acquired by Symantec), Postini, Qualys, Tripwire, Tumbleweed, Valicert and Worldtalk (both of which Tumbleweed acquired). David also teaches computer science at the Keys Middle School in Palo Alto. He received both his A.B. in math and computer science and his M.B.A. degrees from Harvard University.