While we can visualize lattices in 2D and 3D, their true cryptographic strength emerges in hundreds of dimensions. The security relies on a 'trapdoor' mechanism: it's easy to create a complex-looking public key from a simple private key, but computationally impossible to reverse the process without the secret information.
The engine behind this scrambling is a simple mathematical rule, applied thousands of times:
v'Ȉ_i = vȈ_i + k ⋅ vȈ_j
Let's break down what's happening in this equation:
v'Ȉ_i
: The new, updated vector in our basis.
vȈ_i
: An existing vector being modified.
vȈ_j
: Another randomly chosen vector from the same basis (where i ≠ j).
k
: A small, non-zero random integer (e.g., -2, -1, 1, 2).
Each application of this rule is like a single step in thoroughly shuffling a deck of cards. The result is what you see below: a 'Good Basis' that is clean and simple, transformed into a 'Bad Basis' that appears dense and random. Finding the original good basis from the bad one is the computationally hard problem that secures the system.