Stephen Shankland/CNET

As promised, Yahoo is now automatically encrypting Yahoo Mail users' connections to the service.

The company announced Tuesday it has enabled automatic HTTPS as the default for all users on the network, coming in a day before the January 8 deadline it placed on itself in October. With the upgrade, the Web portal has now using 2,048-bit encryption keys to secure certificates, which are used to set up encrypted communications between a Web server and Web browser.

"Anytime you use Yahoo Mail -- whether it's on the web, mobile web, mobile apps, or via IMAP, POP or SMTP -- it is 100% encrypted by default and protected with 2,048 bit certificates," Jeff Bonforte, Yahoo's senior vice president of Communication Product, wrote in a company blog post. "This encryption extends to your e-mails, attachments, contacts, as well as Calendar and Messenger in Mail."

The move is part of the company's efforts to beef up encryption across all of its products in response to concerns about government surveillance activities on the Internet. Since the release of confidential documents this summer by former NSA contractor Edward Snowden describing the NSA's collection of e-mail metadata and other Internet communications, several tech giants have been actively working to make surveillance, authorized or not, significantly harder.

The issue seemed to take on greater prominence for companies in October, when the Washington Post reported that newly surfaced documents showed the NSA secretly accessed data from several tech giants, including Yahoo, by intercepting unencrypted Internet traffic in a program called Muscular.

Google completed encryption efforts similar to Yahoo's in November to heighten the security of information flowing between data centers, while Microsoft and Facebook have announced plans to switch over to stronger 2,048-bit encryption keys in the near future.