The State Department has begun issuing U.S. passports with RFID technology made by its Colorado Passport Agency in Denver, and intends to expand the program to other production facilities through the autumn of 2006. E-passports place an RFID chip in the rear cover that stores the persons name, date of birth, gender, place of birth, and other information printed elsewhere in the passport. It also stores a digital image of the person to whom the passport was issued that includes measurable physical characteristics that can be used as a biometric identifier. To secure the passports electronic data, metallic anti-skimming material is placed on the front cover and spine. Another security measure is use of Basic Access Control technology to authenticate the data prior to unlocking the chip. An electronic signature on the chip is intended to prevent alteration or modification of its data, as well as to validate and authenticate the information. Despite these claims, privacy proponents question the security of e-passports. At the Black Hat security conference in Las Vegas, German researcher Lukas Grunwald reportedly scanned information on a VeriChip RFID chip using a laptop computer with an RFID reader and a smart-card programmer. VeriChips VeriMed Patient Identification System is a human-implantable microchip that uses passive RFID technology to identify patients arriving at emergency rooms. The FDA-approved system is also suitable for use in nursing homes and other medical environments, according to the company. A coalition of card makers and chip vendors has called for standards and best practices to be developed to ensure user privacy when using smart-card technology.