One of the main objectives of server-assisted computation is to reduce the cost of generating public key signatures for ordinary users with their constrained devices. On the other hand, based on nothing more than a one-way function, one-time signatures provide an attractive alternative to public key. signatures. This paper revisits server assisted computation for digital signatures to show server assisted one-time signature (SAOTS) that combines the benefits of these two efficiency solutions. The proposed protocol turns out to be a more computational and round-efficient protocol than previous verifiable-server approaches. In addition, SAOTS offers other advantages like verification transparency, getting rid of public key operations for the ordinary user and proving the server's cheating without storing the signatures. © Springer-Verlag Berlin Heidelberg 2004.