Nowadays the exchange of documents, information and data is fulfilled through an electronic format. This arises security problems (i.e. Authentication, non repudiation and privacy). In order to tackle some security issues, the digital signature allows to strongly identify the signatory and prevents against any signed content violation. However with the evolution of distributed systems, context adaptation appears as a very important constraint in ubiquitous environment especially in pervasive and mobile environments. Indeed the most of electronic documents (e.g. book, journal, certificate etc.) should be adapted to contextual situation. In this paper we propose a new signature mechanism (Morph Digital Signature). It enables any trusted entity to blind or to disclose only authorized parts from document according to user and environment constraints. We have also adapted the morph signature to certificate issues by providing a trust entity the ability to morph their certificates format according to pervasive context.