Google and Facebook have struck a $1.1 billion deal to use Google’s Gmail password resiliency technology to help users regain control of their online accounts, according to people familiar with the matter.

The deal, which will also include Yahoo, has been in the works for several months and is expected to be finalized in the coming days, the people said.

It marks a new milestone in the growing security arms race between the two companies, which have become increasingly competitive in recent years with Amazon and Microsoft, which use similar password resillience technology.

Google has been building a $50 billion password resilience network, which has already built out a $20 billion password recovery tool called Google Passwords.

Yahoo, meanwhile, recently began building out a password recovery system called Password Recovery Assistant, which it says is more sophisticated than its Google Passworks.

Google, which sells a number of software and services to help people recover passwords, said in a blog post Thursday that the deal would help it protect user accounts more quickly and securely than it can today.

It is part of a growing trend among tech companies to roll out new password resolvers at a time when companies such as Facebook and Amazon are using similar technology, said Bruce Schneier, a security researcher and former chief technology officer at Booz Allen Hamilton.

While it is difficult to predict exactly how much data is stored on a user’s account, Schneier said, it’s likely that passwords are stored in a range of places, from websites to apps to cloud storage.

For example, he said, a user could put their email address in a database that stores email addresses, passwords and other similar information.

But even if an email address is stored, Schneiest said, the data that is not stored is often valuable to criminals, hackers and spies.

“If the user had a very specific password, there is the potential for it to be used to log into somebody’s computer,” Schneier told CNN.

“If you don’t have the information, it can be used for anything.

So there’s a big incentive to put it in a data center.”

A company representative declined to comment.

Yahoo said it will use Google PassWise’s password recovery capabilities to help protect users’ email accounts.

It said it is also looking to partner with Google on other password resolver technology.