Mesh is a secure, lightweight grid middleware that is based on the addition of a single sign-on capability to the built-in public key authentication mechanism of SSH using system call interposition. Resources may be added to a Mesh-based grid in a matter of minutes using just five small files and two environment variable settings. Mesh adheres to fundamental security principles and was designed to be compatible with strong security mechanisms including two-factor authentication, SSH bastions, and restrictive firewalls. Mesh uses a remote command model, which is based on stock SSH clients and the syntax and commands already understood by users, thus requires no additional software or knowledge to utilize effectively. Several existing services have been integrated with Mesh to provide resource discovery and query, high performance file transfer, and job management.