Evaluation of the Single Keybit Template Attack

Side Channel leakage is a serious threat to secure devices. Cryptographic information extraction is possible after examining any one of the various side channels, including electromagnetic. This work contributes a new method to achieve such a purpose. The Single Keybit Template Attack (SKTA) is introduced as a means to extract encryption keys from embedded processors and other integrated circuit devices performing DES encryptions by passively monitoring and exploiting unintentional RF emissions. Key extraction is accomplished by creating two templates for each bit value of the key based on instantaneous amplitude responses as a device executes DES operations. The resultant templates are input to a Maximum Likelihood processor for subsequent template discrimination with RF emissions captured from a target device. Plaintext and ciphertext are not necessary for SKTA to function. Using 8-bit microcontroller devices and experimentally collected side channel signals, key extraction is possible after examination of approximately 300 RF emission traces. After consideration of SKTA's capabilities, embedded processors using DES to process sensitive data warrants reconsideration.
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