Information and Communication Technologies, and specifically e-Government developments, occupy a relevant position in the national agenda of many countries worldwide. But development of such projects requires a careful planning, mostly when legal implications are bound to technological systems. This is the case when considering digital signature technology, as an essential element to support trust for e-government services. In this paper, we propose a comprehensive, systemic, and systematic, information assurance process to audit technological solutions for e-government services, and we show examples using digital signature from Costa Rica. Our approach supports applications developed with heterogeneous infrastructure and technologies. It also comprises the entire assurance process, including identification of threats and vulnerabilities, risk analysis, policy definition, and definition of security controls.