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Mod_add

As explained in Elliptic Curve Cryptography for Developers

mod_add is a book-defined routine that computes the sum of two values modulo a modulus.

mod_add computes a modular sum: it adds b and c, reduces the result modulo n, and writes the value to a. The GMP implementation uses a temporary mpz_t value, then clears it. section 2.3

Its execution flow is deliberately small:

  • Clear the temporary value after the output is computed. section 2.3

How Elliptic Curve Cryptography for Developers covers it

How deep it goes
Explains the equation-to-code flow and temporary GMP storage, but does not derive modular arithmetic or GMP internals.
Examples
Uses a complete C/GMP listing showing temporary initialization, addition, reduction, assignment, and cleanup.
What it assumes
Builds on basic modular arithmetic notation and GMP multiple-precision integer operations.
What you can do after
Apply it via GMP by implementing modular addition with explicit output, operands, modulus, temporary storage, and cleanup.
How it connects
Connects modular addition with finite field arithmetic, modular subtraction, modular multiplication, modular division, and modular negation.
Cover of Elliptic Curve Cryptography for Developers
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This explainer was generated by Manning's knowledge graph from the text of Elliptic Curve Cryptography for Developers. The section links point to the parts of the book it draws on.