Off-Memory Decryption of Classified Documents

Secure transmission of information between parties needs robust cryptographic methods to be utilized. In general, information is delivered to its destination through non-secure channels in which a massive number of malicious users or machines may reside. Data sources use end to end encryption to bypass those threats, however, even after safe delivery, the information is still susceptible to altering or stealing attacks due to viruses, Trojans and other kind of threats hidden in end devices. The decrypted message residing in the memory of computers as plain text is vulnerable against malicious software or users which or who may copy, print or share it to unauthorized parties. In this paper, we present a cryptographic device which moves the decryption stage out of the memory of destination computers, so it is not subject to information stealing anymore. We present theory, implementation and evaluation of the approach in detail, and test results show that our device can capture video frames of Full HD resolution on an HDMI link, descramble and show them on the screen at 60 Hz frame rate successfully.