Mini excersises for Lattice SVP CVP

Some mini-sized Shortest Vector Problem (SVP) instances for practice:

Problem 1 (2D - Easy)

Find the shortest non-zero vector in the lattice generated by:

b₁ = (3, 1)
b₂ = (1, 3)

Problem 2 (2D - Medium)

Find the shortest non-zero vector in the lattice generated by:

b₁ = (5, 2)
b₂ = (2, 5)

Problem 3 (3D - Easy)

Find the shortest non-zero vector in the lattice generated by:

b₁ = (2, 0, 0)
b₂ = (1, 2, 0)
b₃ = (1, 1, 2)

Problem 4 (2D - Harder)

Find the shortest non-zero vector in the lattice generated by:

b₁ = (7, 3)
b₂ = (5, 8)

Problem 5 (3D - Medium)

Find the shortest non-zero vector in the lattice generated by:

b₁ = (4, 1, 0)
b₂ = (1, 4, 1)
b₃ = (0, 1, 4)

Hints:

  • Any lattice vector can be written as v = c₁b₁ + c₂b₂ + ... where cᵢ are integers
  • Try small integer combinations first (0, ±1, ±2)
  • Calculate ||v||² = v·v for each candidate
  • The shortest vector has minimal Euclidean norm

Some mini-sized Closest Vector Problem (CVP) instances:

Problem 1 (2D - Easy)

Given the lattice generated by:

b₁ = (3, 0)
b₂ = (0, 3)

Find the closest lattice vector to target: t = (5, 7)

Problem 2 (2D - Medium)

Given the lattice generated by:

b₁ = (4, 1)
b₂ = (1, 4)

Find the closest lattice vector to target: t = (6, 8)

Problem 3 (2D - Harder)

Given the lattice generated by:

b₁ = (5, 2)
b₂ = (2, 5)

Find the closest lattice vector to target: t = (7.5, 9.3)

Problem 4 (3D - Easy)

Given the lattice generated by:

b₁ = (2, 0, 0)
b₂ = (0, 2, 0)
b₃ = (0, 0, 2)

Find the closest lattice vector to target: t = (3, 5, 7)

Problem 5 (3D - Medium)

Given the lattice generated by:

b₁ = (3, 1, 0)
b₂ = (1, 3, 1)
b₃ = (0, 1, 3)

Find the closest lattice vector to target: t = (5, 6, 4)

Problem 6 (2D - Tricky)

Given the lattice generated by:

b₁ = (6, 2)
b₂ = (3, 7)

Find the closest lattice vector to target: t = (10, 10)

Hints:

  • Lattice vectors have form: v = c₁b₁ + c₂b₂ + ... (cᵢ integers)
  • Calculate distance: ||t - v||² for candidate vectors
  • Start with Babai's nearest plane algorithm (round coefficients in basis representation)
  • Check neighboring integer combinations to ensure you found the minimum