Depending on your specific needs or business scenarios, you may first want to choose between different e-signature format options. Viafirma offers support to both basic and most advanced formats. Basic formats These formats provide all necessary elements to create an advanced or recognized electronic signature: XML Signature It is a specification developed under the W3C that allows the signature (fully or partially) of documents using a standard XML notation. XML Signatures offer some advantages over traditional signatures as it's based on plain text format its structure is readable. XML and PKCS#7 are functionally interrelated, but XML is more extensible and is oriented towards signing XML documents. XML signatures can be used to sign data–a resource–of any type, typically XML documents, but anything that is accessible via URL can be signed. An XML signature used to sign a resource outside its containing XML document is called a detached signature; if it is used to sign some part of its containing document, it is called an enveloped signature; if it contains the signed data within itself it is called an enveloping signature PDF-Signature Embedded signature in PDF documents according to ISO-32001 standards. The fact that the signature is embedded in a PDF document format brings this format closer to the ordinary citizen. In other words, an embedded signature in a PDF can be viewed by a user that has a PDF reader, such as Adobe Acrobat Reader. They are used for scenarios in which the end user or users involved in the process are natural people CMS (Cryptographic Message Syntax) / PKCS#7 The Cryptographic Message Syntax (CMS) is the IETF's standard for cryptographically protected messages. Signature binary file used for signature, authentication, hashing and encryption of documents. Primarily designed for exchanging information from e-mails. Uses the PKCS-7 standard. This format also incorporates time stamping information obtained by a TSA (Timestamping Authority). Advanced formats The advanced e-signature formats that viafirma supports are: XAdES - Advanced electronic signature XML PAdES - Advanced electronic signature PDF CAdES - Advanced Electronic Signature CMS