Jon Callas

Active Investor

Senior Computer Scientist at SRI

San Jose, California

Jon Callas, Senior Computer Scientist at SRI is an active investor based in San Jose, California. This profile covers what Jon Callas backs, at which stage, and how founders can reach out in 2026.

Mr. Jon Callas is a Co-Founder of Dark Mail Alliance. Mr. Callas is an Angel Investor. He serves as Advisor at Titaniam. He also serves as Advisor at Ten Eleven Ventures. He was a Co-Founder & served as the Chief Technology Officer at Silent Circle. Prior to joining Entrust, Callas co-founded PGP Corporation which specialized in email and data encryption software. Over the course of more than fifteen years, Callas held leadership functions including CTO and CSO. Most recently, he also served as an operating system security expert with Apple. Additionally, he has held leadership positions with corporations including Wave Systems Corporation, Digital Equipment Corporation and Counterpane Internet Security Inc. He has also authored several Internet Engineering Task Force (IETF) standards including OpenPGP, DKIM, and ZRTP. He serves as an Advisor at ten Eleven Ventures.

Investor type: Angel
Stages: Early Stage Venture
Invests in: Artificial IntelligenceHealthcare & BiotechDigital Health & HealthTechBiotech & PharmaMedTech & Medical DevicesSaaS & EnterpriseConsumer & RetailClimate & Energy
Location: San Jose, California
Typical check: $500K
Past investments: 3

Notable investments

Electronic Frontier FoundationCounterpaneRipcord

How to reach Jon Callas

Angels and operators like Jon Callas reply to specific, personalized notes that show real traction, not mass blasts. Build a verified list, write a note that fits their thesis, and track replies, all on Round Funded.

Frequently Asked Questions

What does Jon Callas invest in?

Jon Callas invests in Artificial Intelligence, Healthcare & Biotech, Digital Health & HealthTech and Biotech & Pharma, typically at Early Stage Venture. Match your sector and stage, then reach out with a personalized pitch.