NCSA Mosaic for MS Windows User Guide: Advanced Features


Access authentication restricts access to a server based on one of the following:
- username- or password-level access authorization
- connection rejection or acceptance based on Internet address
- a combination of the two methods
As a user you do not know if a server is running with restricted capacities until you try to access a file that is protected. When you try to view such a file, the server prompts Mosaic for a user name and password. This information is then passed back to the server. Access is granted or denied as determined by the server's database of approved users.
Your user name and password are sent across the Internet in a coded format to provide security. Two methods are used to encode the name and password:
- UUEncoded
- a semi-secure method of scrambling the data but can be easily UUDecoded if the data stream is intercepted.
- MD5 Message-Digest Algorithm
- a secure method intended for signature applications. The MD5 algorithm is in the public domain. RSA Data Security, Inc. is making it available for review and possible adoption as a standard.
NOTE: Which method Mosaic uses is determined by the server request.

