Online/Offline Signatures for Low-Power Devices

When digital signature is applied on low-power devices, like smart cards, wireless sensors and RFID tags, some specific properties, e.g., better offline storage, more modular and flexible deployment, are desired. To meet these needs, a new variant of the Fiat-Shamir transformation for digital signatures, referred to as Γ -transformation, is introduced and formalized in this work. Following this new transformation approach, some new signature schemes (referred to as Γ-signatures) are presented and discussed. In particular, it is shown that the Γ-signatures for discrete logarithm problem (DLP) developed in this work combine, in essence, the advantages of both Schnorr´s signature and the digital signature standard (DSS), while saving from the disadvantages of them both.