Method and system for protecting documents while maintaining their editability

A method for computer data security, comprising determining if a computer file contains protected data;

• decrypting encoded files;
• re-encoding decrypted files that have been modified;
• determining data usage rights for a process that has been launched, the data usage rights restricting the process by limiting permissible data access commands that can be issued by the process;
• intercepting a data access command issued by the process;
• and
• blocking the intercepted command if the intercepted command accesses protected data, and if the data usage rights indicate that the command is not permissible.

A computer data security system, comprising:

• a file parser for determining if a computer file contains protected data;
• a file decrypter for decrypting encoded files into memory;
• a file encrypter for encrypting files containing protected data;
• and
• a security processor for indicating to a process that data it receives from memory is protected data.