Technology & Computing
ECC vs RSA Security Equivalence Calculator
Compare an elliptic curve key size to the RSA modulus length needed to achieve the same symmetric security strength.
Your inputs
Change any value to update the result instantly.
Equivalent RSA modulus length
~3072-bit RSA
ECC curve size
256 bits
Symmetric security strength
128 bits
Key size reduction factor vs RSA
12 x
ECC achieves equivalent security to RSA with much smaller key sizes because there is no known sub-exponential attack on well-chosen curves.
Formula and working
ECC symmetric security bits ≈ curveBits ÷ 2; equivalent RSA modulus from NIST SP 800-57 mapping table
- 1
Collect the inputs
ECC curve size = 256
- 2
Apply the formula
ECC symmetric security bits ≈ curveBits ÷ 2; equivalent RSA modulus from NIST SP 800-57 mapping table
- 3
Result
Equivalent RSA modulus length = ~3072-bit RSA bits
Frequently asked questions
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
Report a mistake or request an improvement
Tell us if a formula, unit, explanation, or result needs attention. Your message will include this calculator’s name and page.
Related calculators
AES-GCM Nonce Collision & Key Exhaustion Calculator
Estimate the safe number of messages encrypted under one AES-GCM key before random 96-bit nonce collisions become likely.
Password Entropy & Brute-Force Cracking Time Calculator
Calculate a password's entropy in bits and estimate worst-case brute-force cracking time at a given guess rate.
RSA Key Length Security Strength Calculator
Estimate the symmetric-equivalent security strength and relative computational cost of an RSA key length.
Hash Collision Probability & Birthday Attack Calculator
Estimate the probability of a hash collision occurring among a set of hashed items, based on the birthday paradox.
TLS Handshake Latency Overhead Calculator
Estimate the extra round-trip latency added by TCP and TLS handshakes for TLS 1.2, TLS 1.3 1-RTT and TLS 1.3 0-RTT resumption.
Binary, Octal, Decimal & Hexadecimal Multi-Base Converter
Convert a decimal number into binary, octal and hexadecimal representations and see its bit length.