Power Mod Calculator

Compute a^b mod m for arbitrarily large integers using fast modular exponentiation (binary method) - the backbone of RSA and modular arithmetic.

Frequently Asked Questions

What is modular exponentiation?

Computing a to the b mod m efficiently using exponentiation by squaring. It is the backbone of public-key cryptography.

Why is it useful in cryptography?

RSA encryption requires raising messages to large exponents modulo huge primes. Direct computation would overflow; modular exponentiation keeps numbers bounded by m at every step.

Can I use a negative exponent?

Only when a has a modular inverse, that is gcd(a, m) is one. Then a to the minus 1 is the modular inverse and a to the minus n is its n-th power. Otherwise, the inverse does not exist.

Important Disclaimer: Estimates for informational purposes only.

This calculator provides estimates for informational purposes only. Results are based on assumptions and may not reflect actual outcomes. Consult qualified professionals in relevant fields before making important decisions based on these results.