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Attack can be used to encrypt bitstreams also. >3.4 Attack 2: Breaking Authenticity >Therefore the attacker can encrypt an arbitrary bitstream by means of th
by Nokinside 6y ago
Attack can be used to encrypt bitstreams also.
>3.4 Attack 2: Breaking Authenticity
>Therefore the attacker can encrypt an arbitrary bitstream by means of the FPGA as a decryption oracle. The valid HMAC tag can also be created by the attacker, as the HMAC key is part of the encrypted bitstream. Hence, the attacker can set his own HMAC key inside the encrypted bitstream and calculate the corresponding valid tag. Thus, the attacker is capable of creating a valid encrypted bitstream, meaning the authenticity of the bitstream is broken as well
- krilovsky 6y ago> 3.4 Attack 2: Breaking Authenticity > With the first attack, the FPGA can be used to decrypt arbitrary blocks. Hence, it can also be seen as a decryption oracle. Thus,we can also use this oracle to encrypt a bitstream, as shown by Rizzo and Duong in [41], and generate a valid HMAC tag This requires the first stage of the attack to succeed. If it fails and the FPGA cannot be used as a decryption oracle, there's no way to generate a valid encrypted bitstream with the technique outlined in the paper.