SANTA ANA, Calif. (AP) _ A Navy investigator testified Wednesday that a computer disk seized from the brother of a Chinese-born engineer accused of stealing U.S. defense technology secrets contained encrypted files.
Nicholas Mikus, an investigative computer specialist for the Naval Criminal Investigative Service, said the files could only be unlocked with a specific ``key,'' a chain of 113 letters that was stored on a floppy disk.
Mikus was the latest witness called by the government in its case against Chi Mak, an engineer accused of passing sensitive military information to the Chinese government for more than 20 years.
Mak, a naturalized U.S. citizen who worked for Anaheim-based defense contractor Power Paragon, has pleaded not guilty. He is charged with conspiracy to export defense material to China, failure to register as a foreign agent, attempted and actual export of defense articles and making false statements.
His wife, brother and other relatives also have been indicted.
Mak, 66, was arrested on Oct. 28, 2005, after his brother, Tai Mak, and sister-in-law were stopped at Los Angeles International Airport as they tried to board a flight to Hong Kong and Guangzhou, China.
Investigators said they found a disk in their luggage that contained encrypted files on an electronic propulsion system that would make U.S. submarines virtually undetectable underwater.
Mikus said the disk contained a folder labeled ``DLL'' that held three directories filled with encrypted files. The disk also contained three files containing notes from biology lectures and two files of Chinese music, he said.
Mikus did not testify about the contents of the encrypted files but said the encryption was done on Oct. 25, 2005 _ three days before the Maks were arrested.
Prosecutors have said the floppy disk that contained the ``key'' was found inside a white envelope in a drawer in Tai Mak's bedside table. Investigators also said they found three disks from Chi Mak that contained the original, unencrypted files that were found on the disk in Tai Mak's luggage.
Under cross-examination by the defense, Mikus acknowledged that encryption programs more sophisticated than the one used on the seized disk are available for free or for a small fee on the Internet and also come with Windows Vista.
He also said the encrypted files were not ``hidden'' under the two music files, as prosecutors have alleged.
Court papers indicate investigators found documents at Chi Mak's house on the DDX Destroyer, an advanced technology warship, and lists in Chinese asking Mak for information about torpedoes, electromagnetic artillery systems and technology used to detect incoming missiles at his house.
Tai Mak has pleaded not guilty to charges of conspiracy to export defense articles, possession of property in aid of a foreign government, failure to register as a foreign agent and making false statements.