A03: Crypto Treasure Hunt - Grading Rubric

Total Points: 50
Activity Type: In-Class Group Assignment
Group Size: 3-4 students

Assessment of Learning Objectives

This rubric assesses student mastery of:

LO1: Apply cryptographic hash functions to verify data integrity
LO2: Understand the relationship between public and private keys
LO3: Practice signature verification using simplified cryptographic principles
LO4: Analyze security implications of encryption in real-world scenarios
LO5: Collaborate effectively to solve multi-layered cryptographic puzzles

Detailed Rubric

Component	Points	Criteria
1. CORRECT DECRYPTION (LO4, LO5)
Puzzle Decryption	15	Excellent (15 pts): Complete, accurate plaintext message that matches solution exactly. All decryption steps shown clearly. Demonstrates full understanding of cipher method.
	12	Good (12 pts): Correct plaintext with minor spelling errors (1-2 letters wrong). Decryption method shown but some steps incomplete. Core message is identifiable.
	8	Needs Work (8 pts): Partially correct message with multiple errors. Shows attempt at correct method but execution flawed. Missing key information that would prevent finding location.
	3	Minimal (3 pts): Attempted decryption but largely incorrect. Shows minimal understanding of cipher method. Message unintelligible.
2. LOCATION FOUND (LO5)
Physical Clue Retrieval	10	Found (10 pts): Physical clue successfully retrieved and returned to desk. Team demonstrated effective collaboration and problem-solving.
	5	Partial (5 pts): Located general area but required instructor assistance to find exact clue. Shows partial understanding.
	0	Not Found (0 pts): Unable to locate clue. Did not successfully decode location from message.
3. SIGNATURE VERIFICATION (LO1, LO2, LO3)
Mathematical Verification	15	Excellent (15 pts): All calculations correct including: Accurate hash calculation (H) with ASCII values shown Correct signature verification (V = S^e mod n) Proper comparison (H = V) Appropriate conclusion about signature validity All work clearly shown with units/labels
	12	Good (12 pts): Method correct but contains 1-2 minor calculation errors (e.g., arithmetic mistake). Logic and understanding demonstrated. Conclusion would be correct with accurate calculations.
	8	Satisfactory (8 pts): Major calculation error but method shows understanding of verification process. Some steps correct. Shows attempt at systematic approach.
	4	Needs Work (4 pts): Attempted but used incorrect method. Shows minimal understanding of hash functions or signature verification. Work disorganized or incomplete.
	0	Not Attempted (0 pts): Verification section left blank or completely incorrect with no demonstration of understanding.
4. SECURITY REFLECTION (LO2, LO4)
Conceptual Understanding	5	Excellent (5 pts): All three reflection questions answered thoughtfully with clear connection to cryptographic concepts. Demonstrates understanding of: Encryption security and message interception Public key cryptography and asymmetric security Real-world applications with specific examples Answers use proper terminology and show critical thinking.
	4	Good (4 pts): All questions answered with reasonable understanding. May lack depth or use imprecise terminology, but core concepts correct.
	2	Needs Work (2 pts): Questions answered but responses superficial or partially incorrect. Shows limited understanding of security concepts.
	0	Not Attempted (0 pts): Questions left blank or answers show no understanding of cryptographic concepts.
5. PRESENTATION (LO5)
Team Communication	5	Excellent (5 pts): Clear, well-organized presentation covering all required elements: Decryption method explained clearly Location strategy articulated Verification results presented with evidence Key insight demonstrates learning All team members participate meaningfully Time limit respected (5 minutes)
	4	Good (4 pts): All elements covered but presentation lacks polish. May be slightly disorganized or exceed time. Most team members participate. Core concepts communicated effectively.
	2	Needs Work (2 pts): Presentation incomplete (missing 1-2 required elements). Uneven participation with some members not contributing. Unclear communication of concepts.
	0	Not Attempted (0 pts): No presentation or completely inadequate (missing most elements, no team coordination).

Grading Summary

1. Correct Decryption ______ / 15

2. Location Found ______ / 10

3. Signature Verification ______ / 15

4. Security Reflection ______ / 5

5. Presentation ______ / 5

TOTAL SCORE ______ / 50

Grade Conversion

Point Range	Percentage	Letter Grade	Description
46-50	92-100%	A	Excellent understanding of cryptographic concepts
43-45	86-90%	A-	Strong performance with minor errors
40-42	80-84%	B+	Good understanding, some gaps
37-39	74-78%	B	Satisfactory understanding
34-36	68-72%	B-	Acceptable with notable weaknesses
30-33	60-66%	C+	Basic understanding, needs improvement
<30	<60%	C or below	Insufficient understanding of key concepts

Grading Notes for Instructors

Group grades: All team members receive the same score unless there's documented evidence of unequal participation
Partial credit: Be generous with partial credit if students show correct methodology even with calculation errors
Time management: Don't penalize teams that finish early or need extra minutes if quality is maintained
Difficulty adjustment: Consider giving 2-3 bonus points to teams that complete the Hard puzzle compared to Easy
Effort recognition: If a team shows exceptional effort but makes errors, consider 1-2 bonus points for persistence
Academic integrity: Watch for teams copying solutions. If suspected, interview team members individually about their process

Common Deductions

Issue	Deduction
Missing or incomplete work shown (no scratch work)	-2 to -5 pts
Calculations without labels/units	-1 to -2 pts
Incorrect ASCII values used	-3 pts (from verification)
Modulo operation performed incorrectly	-3 pts (from verification)
Unequal team participation (documented)	-5 pts for non-contributors
Exceeding time limit by >5 minutes	-1 pt (presentation)
Plagiarism or sharing answers between teams	0 for entire assignment

Feedback Guidelines

Provide constructive feedback in these areas:

Strengths: Highlight what the team did well (methodology, collaboration, specific insights)
Areas for improvement: Note specific errors or misconceptions with brief explanations
Connection to course: Relate their performance to upcoming topics (e.g., "Your understanding of hashing will help with blockchain concepts")
Encouragement: Especially for teams that struggled, provide positive reinforcement and resources for improvement

Grading Rubric | 50 Points Total | Page 1 of 1