We demonstrate that unmodified commercial Flash memory can provide two important security functions: true random number generation and digital fingerprinting. Taking advantage of random telegraph noise (a type of quantum noise source in highly scaled Flash memory cells) enables high quality true random number generation at a rate up to 10Kbits / second. A scheme based on partial programming exploits process variation in threshold voltages to allow quick generation of many unique fingerprints that can be used for identification and authentication. Both schemes require no change to Flash chips or interfaces, and do not require additional hardware.