Packet J: Bonus 8
Modern devices often implement this cipher in hardware to both increase speed and decrease the attack surface for timing-related side-channel attacks. For 10 points each:
[10m] What cipher won a competition by NIST (“nist”) in 2001 to become the most commonly used standard cipher?
ANSWER: AES [or Advanced Encryption Standard; or Rijndael (“RINE-dale”)]
[10h] Block ciphers like AES can be used to construct this other type of cipher, which include the Chacha and Salsa20 ciphers. These ciphers encrypt plaintext bit by bit by XORing them with an encrypted sequence of characters.
ANSWER: stream ciphers
[10e] The encrypted keystream in a stream cipher must have this property to ensure the ciphertext is unpredictable. An insecure method of generating numbers with this property may rely on the system clock as an initial seed.
ANSWER: pseudorandomness [or randomness; accept random number generation or pseudorandom number generation; accept stochasticity; prompt on RNG or PRNG by asking “what does that stand for?”]
<Illinois B, Other Science> | Packet J - Southampton A, Indiana A, Illinois B, Edinburgh A
| Heard | PPB | E % | M % | H % |
|---|---|---|---|---|
| 81 | 11.60 | 98% | 14% | 5% |
Conversion
| Team | Opponent | Part 1 | Part 2 | Part 3 | Total | Parts |
|---|---|---|---|---|---|---|
| Claremont | Washington B | 10 | 0 | 10 | 20 | ME |
| Georgia Tech A | Minnesota A | 0 | 0 | 10 | 10 | E |
| Missouri B | Carleton College | 0 | 0 | 10 | 10 | E |
Summary
| Tournament | Edition | Match | Heard | PPB | E % | M % | H % |
|---|---|---|---|---|---|---|---|
| California (North) | Main Site | ✓ | 3 | 13.33 | 100% | 33% | 0% |
| California (South) | Main Site | ✓ | 4 | 15.00 | 100% | 25% | 25% |
| Canada | Main Site | ✓ | 12 | 11.67 | 100% | 17% | 0% |
| Florida | Main Site | ✓ | 3 | 10.00 | 100% | 0% | 0% |
| Great Lakes | Main Site | ✓ | 5 | 10.00 | 100% | 0% | 0% |
| Lower Mid-Atlantic | Main Site | ✓ | 9 | 10.00 | 89% | 0% | 11% |
| Midwest | Main Site | ✓ | 8 | 13.75 | 100% | 38% | 0% |
| Northeast | Main Site | ✓ | 5 | 16.00 | 100% | 40% | 20% |
| Overflow | Main Site | ✓ | 3 | 13.33 | 100% | 33% | 0% |
| South Central | Main Site | ✓ | 2 | 10.00 | 100% | 0% | 0% |
| Southeast | Main Site | ✓ | 8 | 10.00 | 88% | 0% | 13% |
| UK | Main Site | ✓ | 6 | 10.00 | 100% | 0% | 0% |
| Upper Mid-Atlantic | Main Site | ✓ | 9 | 11.11 | 100% | 11% | 0% |
| Upstate NY | Main Site | ✓ | 4 | 10.00 | 100% | 0% | 0% |