Abstract. We believe that fundamental to the establishment of a grid computing framework where all (not just large organizations) are able to effectively tap into the resources available on the global network is the establishment of trust between grid application developers and resource donors. Resource donors must be able to trust that their security, safety, and privacy policies will be respected by programs that use their systems. In this paper, we present a novel solution based on the notion of certified code that upholds safety, security, and privacy policies by examining intrinsic properties of code. Certified code complements authentication and provides a foundation for a safe, secure, and efficient framework that executes native code. We describe the implementation of such a framework known as the ConCert software. 1 Introduction In recent years, numerous organizations have been vying for donated resources for their grid applications. Potential resource donors are inundated with worthwhile grid projects such as discovering a cure for AIDS, finding large prime numbers, and searching for extraterrestrial intelligence. Part of the difficulty in obtaining resources is establishing trust between the grid application developer and the resource donors. Because resource donors often receive little or no direct reward for their contributions, they demand assurances of safety, security, and privacy to protect themselves from malicious as well as simply unreliable software. In an ideal grid framework, as proposed in Legion [18], users are provided the abstraction of a single virtual machine that automatically distributes work and gathers results. In such a framework, this issue is even more salient because the exchange of code happens automatically.

To make development of grid applications less arduous, a natural, powerful, and convenient programming interface is required.

To make development of grid applications less arduous, a natural, powerful, and convenient programming interface is required.

Grid computing has become increasingly popular with the growth of the Internet, especially in large-scale scientific computation. Computational Grids are characterized by their scale, their heterogeneity, and their unreliability, making the creation of Grid software quite a challenge. Security concerns make the deployment of Grid infrastructure similarly daunting.

Grid computing has become increasingly popular with the growth of the Internet, especially in large-scale scientific computation. Computational Grids are characterized by their scale, their heterogeneity, and their unreliability, making the creation of Grid software quite a challenge. Security concerns make the deployment of Grid infrastructure similarly daunting. We argue that functional programming techniques, both wellknown and new, make an excellent practical foundation for Grid computing. We present a prototype Grid framework called Con-Cert built entirely in Standard ML which allows for the trustless dissemination of Grid programs through the use of certified code. The framework is fault-tolerant and relatively easy to implement, owing to a simplified network abstraction. This network abstraction is tedious to program for directly, so we present a high level ML-like language Grid/ML and a compiler Hemlock for the language. Categories and Subject Descriptors D.3.2 [Programming Languages]: Language Classifications—Concurrent, distributed, and

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