In order to protect source code, a system for encrypting schema files and use of the encrypted files in EDM is implemented. The encryption is symmetAET 2023-02-28 Deprecated/incorrectric, which means that a file encrypted with an encryption key, the file is decrypted with the same key. The encryption is done with the windowscrypt.execommand line program with two commands, -enc and -dec. The commands with parameters are:
Encryption: crypt -enc <input file> <crypted file> <key value>
Decryption: crypt -dec <crypted file> <output file> <key value>
An encrypted file can be compiled by the EDM compiler without supplying the enc/decryption key. This can be done since the enc/decryption key is saved in a safe way in the encrypted file. By this feature a customer can install software without having the possibility to see the source code.
In case of problems at customer system using encrypted source, it is possible to decrypt and see the source. Normally the  EDMsupervisor  commands displaying source will give the error message "No source of schema available". But if the enc/decryption key is supplied by the  EDMsupervisor  command System Adm>Set decryption key, the displaying source commands will display source code as if the source is not encrypted.