Security problem is one of the most important aspect in the world of information
technology, such as: security of documents. Today, most of the documents using
Microsoft Office applications. To overcome the security problems of this document, the
author approaches the data encryption technology using Blowfish algorithm. A data
encryption technology to ensure that the information that flows in a session is not
intercepted or modified others. Blowfish or often called "OpenPGP.Cipher.4" is a
Symmetric Cryptosystem, using the same key for encryption and decryption.
This research is divided into 2 part. The first is the implementation of the Blowfish
algorithm in the programming language Visual Basic 6.0 to be a desktop model based
Cryptosystem. The Second thing is testing key and several Microsoft Office file
extensions, and testing of additional tools useful Folder Lock to lock the folder.
The result said that the implementation in Windows operation system is
successful. All Microsoft Office file types including Microsoft Word files (. Doc,. Docx,.
Rtf,. Txt), Microsoft Excel (. Xls,. Xlsx), Microsoft Access (. Mdb) and Microsoft
PowerPoint (. Ppt,. Pptx) can do encryption and decryption process.
Keyword: Cryptography, Blowfish Algorithm, Microsoft Office, Symmetric Cryptosystem, Secret Information.