"Security is about who you trust," Schneier said. "Do you trust Google more than your sysadmin? Do you trust Google Docs more than Microsoft Office?"
"Trust is social," he said. "It’s not technical."
Yes, I trust that a Google Employee, whose sole function is to maintain the system, will ensure that the system is secure, patched and up-to-date. It is simply about Reputational risk. Reputational risk (damage to an organization through loss of its reputation or standing), can arise as a consequence of operational failures. Every company understands reputational risk, particularly businesses who regard their brand as one of their most critical assets. Google is one of them. They have a reputation to maintain.
NIST just published a working draft of the Cloud Computing Security presentation. Some of the Security Advantages mentioned in the presentation are:
- Shifting public data to a external cloud reduces the exposure of the internal sensitive data
- Cloud homogeneity makes security auditing/testing simpler
- Clouds enable automated security management
- Redundancy / Disaster Recovery
- Data Fragmentation and Dispersal
- Dedicated Security Team
- Greater Investment in Security Infrastructure
- Fault Tolerance and Reliability
- Greater Resiliency
- Hypervisor Protection Against Network Attacks
- Possible Reduction of C&A Activities (Access to Pre-Accredited Clouds)
- Simplification of Compliance Analysis
- Data Held by Unbiased Party (cloud vendor assertion)
- Low-Cost Disaster Recovery and Data Storage Solutions
- On-Demand Security Controls
- Real-Time Detection of System Tampering
- Rapid Re-Constitution of Services
- Advanced Honeynet Capabilities
I understand that these will depend on the actual implementation. It usually does for everything. For e.g. you can create world’s most secure cipher, but the poor implementation is usually the weakest link.
But in theory, if cloud services are implemented properly, I think NIST’s list of advantages hold true.