Mixed-media data, such as that including animation data (801), model data (802) and texture data (803) along with other media data types is encoded. To prevent unauthorized access. The data types are combined to produce a mixed-media data file (805). Passwords are added to produce an internal file with passwords (1103). A file key (1202) is combined with a program key (1203) to produce an encryption key (1204). The encryption key is used to encrypt the internal file (1103) to produce an encrypted internal file (1302). The file key (1202) is added to the encrypted internal file as part of a header to produce a coded export file (1401). In this way, a plurality of access keys may exist each providing different levels of access to a user.