All messages sent between SuiteBox and the CRM are validated by a token sent from SuiteBox to ensure the authenticity of the sender.
The storage of the files in the Amazon S3 Data centre. Details of S3's design are not made public by Amazon, though it clearly manages data with an object storage architecture.
S3 is designed to provide 99.999999999% durability and 99.99% availability of objects over a given year, though there is no service level agreement for durability.
SuiteBox ensure that all information that comes to the cloud comes through HTTPS.