Cloud computing has advanced to the point where its living up to much of the hype and promise of recent years. That was one of the messages coming from some of the participants at the International Cloud Computing Conference and Expo being held in New York City this week.Another key message that came through loud and clear is that security is still a major concern for companies considering the adoption of cloud services. Security, in fact, was one of the main topics of discussion in the conference sessions.Attendees listened to speakers discussing topics such as business-critical security and compliance in the cloud, leveraging the cloud to enable identity driven security, high availability in the cloud -- architectural best practices, public cloud adoption with sensitive data, and using single sign-on to access cloud-based services.Vendors participating at the gathering acknowledged that security is still a major stumbling block to cloud adoption."Security always comes up as one of the key concerns," particularly with public cloud offerings, says Theresa Vu, product marketing manager at VMware, one of the speakers at the conference.Another speaker, Scott Chasin, chief technology officer, Content & Cloud Security at McAfee, points out that while security remains a challenge for cloud providers, security solutions are now being made available via the cloud. "A lot of innovation is being delivered from cloud providers," he says.