A method of secure file conversion is disclosed. The method includes storing a decrypted version of a previously encrypted file, the encryption and decryption occurring using public key infrastructure, in an allotted memory location of a memory for which read-only access to the stored decrypted file is provided. Next, the memory location is monitored for an attempt to access at least one memory location other than the allotted location. Finally, a file format of the stored decrypted file is converted, the conversion being aborted upon detecting attempt to access at least one memory location other than the allotted memory location. A converter is further disclosed.