Software & Apps > File Types What Is a DDOC File? Some are digital documents, and others are images or macro files By Tim Fisher Tim Fisher Facebook Twitter Senior Vice President & Group General Manager, Tech & Sustainability Emporia State University Tim Fisher has more than 30 years' of professional technology experience. He's been writing about tech for more than two decades and serves as the SVP and General Manager of Lifewire. lifewire's editorial guidelines Updated on August 5, 2022 Tweet Share Email Tweet Share Email File Types File Types Apps Windows MS Office Linux Google Drive Backup & Utilities Design Cryptocurrency What to Know Some DDOC files are digital signature files that work with DigiDoc4 Client.Others are macro files or graphic files. This article explains what a DDOC file is and how to open one. What Is a DDOC File? A file with the DDOC file extension is a DigiDoc digital signature file that stores encrypted data. .DDOC is the file extension used in the first generation DigiDoc format, while the latest version uses .BDOC and stands for a Binary Document file. Encrypted DigiDoc files use the .CDOC suffix instead. These DigiDoc formats were developed by RIA. You can read more about the file format used with DigiDoc on their DigiDoc File Formats page. If not a DigiDoc file, your particular DDOC file may be a Digital Mars C, C++, or D macro file. Another possible format may be a graphic file used with Apple's now-discontinued MacDraw software. Although they look similar, DDOC files have nothing at all to do with ADOC files or Microsoft DOC and DOCX file formats. How to Open a DDOC File DigiDoc4 Client should be able to open DDOC files on Windows, Linux, and macOS. There's also the DigiDoc iOS app and DigiDoc for Android. This software is also used to authenticate government-issued ID cards, so it can both check that a document is signed and save documents (like Excel, Word, or PDF files) in this encrypted signature format. Depending on the version you're using, you may see this alert when you try opening the file: The current file is a DigiDoc container that is not supported officially any longer. You are not allowed to add or remove signatures to this container DigiDoc can open other document formats, too, including not only BDOC, ADOC, and EDOC, but also ASICE, SCE, ASICS, SCS, and PDF. We're not entirely sure how DDOC files work with them, but if yours isn't a DigiDoc file, then it's probably associated with Digital Mars compilers. MacDraw was a vector drawing application released with Mac computers in 1984. It evolved into MacDraw Pro and then ClarisDraw in 1993, but isn't available for download or purchase anymore. It's probably highly unlikely that your file has anything to do with MacDraw. Your specific file could be saved in a format that has nothing to do with any of the formats already mentioned here, in which case a totally different program is required to open it. If you think this may be true, try opening it with a free text editor to see if there's any identifiable text that can help you understand what program was used to create the file. You can then use that information to research a DDOC viewer or editor. If one program on your computer tries to open DDOC files but shouldn't, or you've accidentally associated these extensions with an unrelated program (like MS Word), changing this default "open with" application is easy to do in Windows. How to Convert a DDOC File A free file converter is normally the way to go for converting one file format to another, but it's unclear if there are any converter tools that support these DDOC formats. The only other way to convert a file is to use the software that opens it, via its save or export option. This might be possible with DDOC files that are used with Digital Mars software, but we don't imagine that's also true for DigiDoc files. Still Can't Open Your File? Like you read in the note at the top of this page, some file formats use file extensions that look like they could be related to each other, like DOC and DDOC. This is usually a misunderstanding of the formats, which can lead to trouble when you try opening them. For example, DOC files open in word processor programs and can't be used with DigiDoc or any other DDOC compatible software. The same is true the other way around, where DDOC files aren't compatible with Microsoft Word programs or other text editors. This concept can be applied to other file extensions and their related formats, like DCD files, which could be DesignCAD drawing files or DisCryptor encrypted databases. DivX descriptor files that use the DDC and DDCX file extension is another example. If you don't really have a DDOC file, research the file's real file extension to see which program you need to view, edit, or convert it. Was this page helpful? Thanks for letting us know! Get the Latest Tech News Delivered Every Day Subscribe Tell us why! Other Not enough details Hard to understand Submit