Symantec announced today it has paid $370 million to buy encryption firms PGP Corp. and GuardianEdge Technologies.

The move represents a shift into an adjacent market for Symantec, which focuses on antivirus and other security measures for both corporations and consumers.

Under the deals, Symantec is buying PGP for $300 million and GuardianEdge Technologies for $70 million, both in cash. The deals are subject to regulatory approval and are expected to close next quarter.

Encryption is becoming an increasingly important part of security as critical data flows freely into mobile devices and the Internet cloud and as criminal hackers become more and more adept at breaking into company networks. It’s like an extra layer of defense to protect data, once an outer network has been compromised.

With these two companies, Symantec gains top-notch technology for encrypting data on hard drives, removable media such as thumb drives, emails, single files, folders, and smartphones. The encryption market itself is expected to be about $1.7 billion in 2013, according to market researcher IDC.

Symantec expects these transactions to be 2 cents dilutive to non-GAAP earnings per share in fiscal year 2011 and accretive to its non-GAAP earnings per share in fiscal year 2012. That is, it will take time before there’s a payoff in profits.