Digital signatures are gaining prominence in practice, facilitating electronic transactions and streamlining document management. Digital signatures are used in several aspects of life, including tax declarations, electronic contract execution, authentication in securities transactions, bidding, and sales. Nonetheless, the adoption of digital signatures by small and medium-sized organizations encounters challenges, including substantial expenses associated with acquiring digital certificates for all employees or establishing an internal PKI infrastructure. In this article, we present a low-cost solution for signing electronic documents without PKI infrastructure for small and medium-sized enterprises. The idea of this solution is to propose an identity-based signature scheme according to the EdDSA standard that is safe and effective. We conduct a security analysis, compare the computational cost with some other publications, and evaluate the installation performance of the proposed identity-based signature scheme.