Flashcards on Fundamentals of Cryptography
Fundamentals of Cryptography: A Student's Guide
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Cryptographic Attacks
11 cards
Card 1
Question: What is the estimated total Bitcoin network hashing power given in the content (in TH/s and H/s)?
Answer: 140 TH/s = 1.4 × 10^14 H/s (noting 2× SHA-256 makes it effectively 2^48 H/s in the example).
Card 2
Question: How many effective hash attempts per second does the content equate to for the Bitcoin network when comparing to AES (assuming AES speed ≈ SHA-256)?
Answer: Equivalent to about 2^48 H/s (used to estimate brute-force attack capability against symmetric keys).
Card 3
Question: Using the Bitcoin network's hashing power, how long would it take to brute-force a 56-bit AES key (approximate)?
Answer: About 4 minutes.
Card 4
Question: Using the Bitcoin network's hashing power, how long would it take to brute-force an 80-bit AES key?
Answer: About 136 years.
Card 5
Question: Using the Bitcoin network's hashing power, how long would it take to brute-force a 128-bit AES key according to the content?
Answer: About 10^17 years (far greater than the age of the Universe ~10^10 years).
Card 6
Question: What are the reported peak performance and estimated hash-rate equivalent for the Fugaku supercomputer (2020)?
Answer: Speed = 4 × 10^17 ≈ 2^59 FLOPs, which corresponds to about 2^45 H/s (using 1 H ≈ 12,000 FLOPs).
Card 7
Question: According to Fugaku's estimated performance, how long to brute-force AES keys of 56, 80, and 128 bits?
Answer: 56-bit: ~32 minutes; 80-bit: ~1,000 years; 128-bit: ~10^18 years.
Card 8
Question: What are the estimated electricity costs to brute-force AES keys using Fugaku-level resources for 56-bit and 80-bit keys?
Answer: 56-bit: ~$1,500; 80-bit: ~$6.5 billion.
Card 9
Question: What RSA factorization milestones and resource efforts are reported (with bit lengths and years)?
Answer: 2009 RSA-232 (768 bits) — 2,000 core-years (or ~2^67 instructions); 2019 RSA-240 (795 bits) — 4,000 core-years; 2020 RSA-250 (829 bits) — 2,700 core-y
Card 10
Question: What discrete logarithm (DLP) results in Z_p are reported and their resource efforts?
Answer: 2016: 768-bit prime DLP — 6,600 core-years; 2019: 795-bit prime DLP — 3,100 core-years.