NEW YORK ( TheStreet) - Investors seem unperturbed by LinkedIn's ( LNKD) hacking incident earlier this week.

The professional network has yet to reveal how many passwords were stolen and how many users were impacted by Wednesday's incident, but shares climbed 1.13% to close at $94.13 on Thursday, outperforming the NASDAQ. The stock is up over 49% this year.
LinkedIn investors have shrugged off the company's hacking incident.

Shares of the professional networking site, which managed accounts for 161 million professionals globally as of March 31, 2012, dipped only slightly on Wednesday while rumors about the security of the site and the safety of users' personal information circulated. After LinkedIn director Vincente Silveira confirmed that "some of the passwords that were compromised correspond to LinkedIn accounts" on the company blog, LinkedIn's shares recovered, closing at $93.05 - an increase of 0.09%.

In his blog post, Silveira assured users "that members whose passwords have not been compromised benefit from the enhanced security we just recently put in place, which includes hashing and salting of our current password databases."

Hashing and salting aims to make passwords much harder to crack. Salting adds a string of characters to a password before they are 'hashed', or masked.

Silveira also directed users to the site's best practices for account security, which include using long, complex passwords, changing passwords frequently and creating unique passwords for every online log-in.

"News of a possible LinkedIn hack is a good reminder to all internet users on the importance of maintaining an ever-changing and complex password," added Jim Walter, manager of the Intel's ( INTC) McAfee Threat Intelligence Service, in a statement. "A secure passphrase may be the only thing standing between your personal data and those that wish to steal it."

LinkedIn is the preferred site for recruiters and job seekers, according to a report released by Bullhorn Reach, a social recruiting platform that helps recruiters leverage social media more efficiently, on Tuesday. LinkedIn hosts 77% of job openings posted online, leading Twitter and Facebook ( FB), the report said.

eHarmony, the popular online dating site, was a target of a password hacking scheme on Wednesday as well; however, only a small fraction of user passwords were compromised, according to the company's blog.

Like LinkedIn, eHarmony reassured its users of its "robust security measures, including password hashing and data encryption, to protect our members' personal information."

Investors seem to be satisfied that both companies are continuing to investigate the security breaches, but another hacking incident in the world of social networking may cause traffic to slow and investor confidence to wane.

--Written by Nathalie Pierrepont in New York.

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This article was written by a staff member of TheStreet.