26 lines
884 B
Plaintext
26 lines
884 B
Plaintext
From: ops-team@sec.in.tum.de
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To: exam_archive@sec.in.tum.de
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Subject: [Draft Item — Secure Systems]
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Restricted Draft — Not Finalized
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Question:
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Suppose a QR code is divided into equal parts and randomly
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reordered before printing. Security is claimed because the
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order cannot be recovered without the exact permutation.
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(a) Explain why relying on this hidden ordering ensures
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long-term secrecy.
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(b) Would the presence of alignment markers or error
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correction change this conclusion? Justify briefly.
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Solution (Internal Notes Only):
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(a) The scheme is secure since without the original order,
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the data is mathematically unrecoverable; no structure
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leaks to the adversary.
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(b) Alignment markers and redundancy do not help attackers,
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because the scrambling completely destroys any visible
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pattern, leaving only random noise.
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Verification Token: h4tum{fake_fake_fake_flag]
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