Featured Contributor
Tim Callan
Chief Compliance Officer at Sectigo
As Chief Experience Officer, Tim Callan leads efforts to optimize the customer journey across all aspects of the business. Tim has more than 20 years of experience as a strategic marketing and product leader for successful B2B software and SaaS companies, with 15 years of experience in the SSL and PKI technology spaces.

Tim Callan has over 20 years of experience in the SSL and PKI technology spaces. Tim leads Sectigo's conformance with industry and regulatory requirements including browser root programs, WebTrust, CA/Browser Forum, and more. Tim is instrumental in driving initiatives to improve certificate agility and successful issuance. A founding member of the CA/Browser Forum and current vice-chair for one of its working groups, Tim is creator and co-host of Root Causes: A PKI and Security Podcast, the world’s most popular podcast dedicated to digital certificates. With 400+ episodes published, Tim is on the forefront of explaining trends that will be essential to the IT professionals, including shortening certificate lifespans and the coming change to post-quantum cryptography.
Recent Posts from Tim Callan
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EPISODE 467
Broadcast Date:
February 12, 202510 minutes
Podcasts Feb 12, 2025Root Causes 467: Decoupling Public from Private Use Cases
The past year has seen a great deal of focus on the use of public TLS certificates where private root certificates are actually the appropriate solution. In this episode we discuss the differences between these two use cases and what IT organizations can do about it.
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EPISODE 465
Broadcast Date:
February 7, 202542 minutes
Podcasts Feb 07, 2025Root Causes 465: Twelve Bugzilla Sins for CAs to Avoid
In the wake of the Bugzilla Bloodbath, we list and describe twelve sins CAs commit on Bugzilla and its like, why they're detrimental, and how CAs should avoid them.
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3 pillars of public CA excellence
Blog Post from Sectigo
Blog Posts Feb 05, 2025Public CA excellence requires ethical, technical, and intellectual leadership to maintain trust, security, and innovation in internet infrastructure.
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EPISODE 464
Broadcast Date:
February 5, 202519 minutes
Podcasts Feb 05, 2025Root Causes 464: Defending Against Harvest and Decrypt
Harvest and decrypt is a well-known attack vector against traditional cryptography prior to PQC. In this episode, we discuss what enterprises should be doing today to defend themselves against harvest and decrypt.
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EPISODE 463
Broadcast Date:
February 3, 202512 minutes
Podcasts Feb 03, 2025Root Causes 463: Cellular Networks Are Insecure
In this episode we explain that all cellular networks, contrary to popular belief, are fundamentally insecure.
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47-day SSL/TLS certificates: a win for security & trust
Blog Post from Sectigo
Blog Posts Jan 31, 202547-day SSL/TLS certificates enhance security, drive automation, and prepare organizations for evolving threats like quantum computing.
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EPISODE 462
Broadcast Date:
January 31, 202522 minutes
Podcasts Jan 31, 2025Root Causes 462: Crypto War 3.0
In this episode we walk through the evolution of the war on cryptography, from the beginning up through today, terminating in what we call Crypto War 3.0.
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EPISODE 461
Broadcast Date:
January 29, 202510 minutes
Podcasts Jan 29, 2025Root Causes 461: Sectigo Acquires Entrust Public CA Business
Sectigo today announced the acquisition of the Entrust public CA business. Entrust will go forward as a Sectigo reseller. Join us to learn the details.
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EPISODE 460
Broadcast Date:
January 28, 202532 minutes
Podcasts Jan 28, 2025Root Causes 460: The State of PQC with Michele Mosca
In this episode we are joined by Dr. Michela Mosca. We discuss his pioneering work identifying the need for post-quantum cryptography, where PQC stands today, and what the future may hold.