Secure File Transfer for Business-to-Business

SFTP can be used to transfer files securely within and between businesses, as shown in Figure 4. Deploying SFTP servers at strategic intranet and extranet locations creates a cross-platform file sharing infrastructure for interacting with and delivering work products to business units, customers, and partners. In this example, the accounting department uses SFTP to deliver financial spreadsheets to an outside auditor and purchase orders to a manufacturer. Online delivery increases business efficiency, but only authorized parties must be permitted to access these files. By combining password and public-key authentication, this company verifies recipient identity before sending any file. By using MACs to detect modification, recipients are assured that copied files remain authentic.

Figure 4: Secure Business-to-Business

In business-to-business transactions, organizations are usually unable to dictate the operating system, server, or client software employed by others. For example, consider consultants delivering confidential reports and IT service companies delivering software patches to customers. These situations require a platform-independent solution that can be deployed quickly, with minimal investment, accommodating any customer. File transfer based on Secure Shell is well suited because low or no-cost software is readily available for nearly every OS, and interoperability issues are relatively uncommon.

While there are many business motivations to protect the confidentiality of transferred files, legislation is a factor of increasing importance. In the US, federal, state, and local governments have enacted privacy legislation, requiring businesses to define policies that limit disclosure of personally-identifiable information. The European Union Data Protection Directive requires that information transfer to a third country only take place if certain conditions are met. This directive applies not just within the EU, but to any company doing business with European nationals.