In the wake of revelations about the National Security Agency's monitoring of traffic on the private international fiber links connecting the data centers of Google and Yahoo, Google stepped up its efforts to encrypt internal server traffic and block such monitoring. Now, Yahoo has announced its own plans to encrypt all information that travels between data centers by early next year.

In a blog post, Yahoo CEO Marissa Mayer reiterated that "Yahoo has never given access to our data centers to the NSA or any other government agency. Ever." Yahoo previously announced that it would protect Yahoo Mail sessions by default with Secure Socket Layer encryption by January 8, using a 2048-bit encryption key. Google moved to encrypt all its searches earlier this fall, and the company has enabled SSL encryption by default for users logged into its services since 2011.

In addition to encrypting traffic between its data centers by March of 2014, Yahoo is also moving to apply SSL encryption across all its websites within the same time frame. And Mayer said that Yahoo will "work closely with our international Mail partners to ensure that Yahoo co-branded Mail accounts are HTTPS-enabled."

The move will increase the privacy of Yahoo users, but it also comes after Yahoo's Web sessions and internal data center traffic were revealed to at one point be the largest single source of data collected by the NSA, according to documents shared by former NSA contractor Edward Snowden.