This page is part of the Da Vinci Clinical Documentation Exchange (v0.1.0: STU 1 Ballot 1) based on FHIR R4. The current version which supercedes this version is 1.1.0. For a full list of available versions, see the Directory of published versions

Base64 Encoded Content

Previous Page

Base64 Encoding Content

This Guide requires the use of Base64 encoding for embedding non XML documents and graphics. Also the authors acknowledge that Base64 encoding may present rendering challenges in some browsers.

Purpose of Base64 Encoding

The purpose of Base64 Encoding is to eliminate characters and binary representation that may interfere with the messaging standards used to exchange a specific payload (in the case of this Guide, the C-CDA). Base64 Encoding uses an algorithm that transforms the payload into a specific set of 64 characters that are both members of a subset common to most encodings, and also printable. For example, MIME’s Base64 implementation uses A-Z, a-z, and 0-9 for the first 62 values. Other variations share this property but differ in the symbols chosen for the last two values.

Standards for Base64 Encoding

In both CDA and FHIR, the body of an unstructured CDA must be Base64 encoded and decoded as defined in RFC 4648.

Next Page