Speaking to CNBC Tuesday, AOL CEO Tim Armstrong said that there will be a "huge investment" in security when building the new AOL-Yahoo! merged brand, Oath.

"I think that consumers know that there's a possibility when you are using the internet, trust is the most important thing," Armstrong said. "We're putting a huge investment into security to resolve that situation."

Armstrong also said the Oath partnership agreement predated knowledge of Yahoo!'s massive 2014 security breach, which was revealed in October. "Marissa (Meyer) had been dealing with it. I think they're doing a good job focusing on it, and fixing the issues."

Why it matters: With billions of users across over 20 brands, the merger between AOL and Yahoo! will give Verizon access to a wealth of user data, and email data in particular. While AOL is no longer a top email client, the AOL email brand still houses millions of users' data, and is seeing spikes as Verizon migrates its email clients to AOL ahead of the merger. Assuring AOL email users that their data will be secure when merged with Yahoo!'s brand, and potentially Yahoo!'s email domain, will be a priority for Oath as it focuses on retaining users across throughout the brand merger.