Knowledge Base
Elliptic-Curve Parameter
A

prime256v1

Summary

Name:
prime256v1
Long Name:
prime256v1 elliptic curve (256-bit prime field)
Key size:
256 bits
Object identifier:
1.2.840.10045.3.1.7
Aliases:
SECP256R1, P-256, ECPRGF256Random, 256-bit Random ECP Group

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Security

A+
Key Size
Security

The elliptic-curve cryptography[118][119][120][121] is an approach to public-key cryptography[164][165][166] based on the elliptic curve[116][117]s. The most important property in terms of encryption strength, beyond the designer is elliptic curve key size[292][293][294]. All the key sizes available are considered secure, so there is no consideration about it.

A
Trusted Design
Security

The elliptic-curve cryptography[118][119][120][121] is an approach to public-key cryptography[164][165][166] based on the elliptic curve[116][117]s. Note that there is controversy[287][288][289][290][291] around some of the National Institute of Standards and Technology[470][471] designed elliptic curveselliptic curves designed by NIST[285][286].

Recommendations

Add at least one elliptic curve to the list of elliptic curves supported by your server designed by independent researchers and prefer them as server configuration makes it possible.

A
Post-Quantum
Security

The elliptic curve[116][117] cryptography provides no protection against a cryptanalytic attack by a quantum computer, and no classical elliptic curve does — just as classical Diffie-Hellman does not — because a quantum computer breaks the hardness assumption they rely on. Only a hybrid key exchange (a classical algorithm combined with a post-quantum cryptography[158][159] one) or a pure post-quantum algorithm is quantum-safe.

Recommendations

Enable a hybrid key exchange or a pure post-quantum algorithm on your server, and prefer it where the configuration allows, so the connection stays secure against a future quantum computer.

Parameter Numbers

Prime (p)
0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff
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Coefficient (a)
0xffffffff00000001000000000000000000000000fffffffffffffffffffffffc
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Coefficient (b)
0x5ac635d8aa3a93e7b3ebbd55769886bc651d06b0cc53b0f63bce3c3e27d2604b
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Generator (x)
0x6b17d1f2e12c4247f8bce6e563a440f277037d812deb33a0f4a13945d898c296
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Generator (y)
0x4fe342e2fe1a7f9b8ee7eb4a7c0f9e162bce33576b315ececbb6406837bf51f5
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Order (n)
0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551
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Cofactor (h)
0x1
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Representations

PEM

-----BEGIN EC PARAMETERS-----
BggqhkjOPQMBBw==
-----END EC PARAMETERS-----
Download ecparam.pem
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PARI/GP

p = 0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff;
a = 0xffffffff00000001000000000000000000000000fffffffffffffffffffffffc;
b = 0x5ac635d8aa3a93e7b3ebbd55769886bc651d06b0cc53b0f63bce3c3e27d2604b;
E = ellinit([a, b], p);
G = [0x6b17d1f2e12c4247f8bce6e563a440f277037d812deb33a0f4a13945d898c296, 0x4fe342e2fe1a7f9b8ee7eb4a7c0f9e162bce33576b315ececbb6406837bf51f5];
n = 0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551;
h = 0x1;
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LaTeX

$\begin{aligned}
y^2 &\equiv x^3 + a x + b \pmod{p} \\
p &= 0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff \\
a &= 0xffffffff00000001000000000000000000000000fffffffffffffffffffffffc \\
b &= 0x5ac635d8aa3a93e7b3ebbd55769886bc651d06b0cc53b0f63bce3c3e27d2604b \\
G &= (0x6b17d1f2e12c4247f8bce6e563a440f277037d812deb33a0f4a13945d898c296, 0x4fe342e2fe1a7f9b8ee7eb4a7c0f9e162bce33576b315ececbb6406837bf51f5) \\
n &= 0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551 \\
h &= 0x1
\end{aligned}$
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