Knowledge Base
Elliptic-Curve Parameter
A

c2tnb239v2

Summary

Name:
c2tnb239v2
Long Name:
c2tnb239v2 elliptic curve (binary field GF(2^239))
Key size:
239 bits
Object identifier:
1.2.840.10045.3.0.12
Publishers:

Check your host!

Type a URL to analyze a service

Get a prompt and clear overview of your security configuration. Right now!

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]. This elliptic curve designed by independent researcher[284] Daniel J. Bernstein[476][477] and there is no evidence for any compromise.

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

Coefficient (a)
0x4230017757a767fae42398569b746325d45313af0766266479b75654e65f
Copy to clipboard
Coefficient (b)
0x5037ea654196cff0cd82b2c14a2fcf2e3ff8775285b545722f03eacdb74b
Copy to clipboard
Generator (x)
0x28f9d04e900069c8dc47a08534fe76d2b900b7d7ef31f5709f200c4ca205
Copy to clipboard
Generator (y)
0x5667334c45aff3b5a03bad9dd75e2c71a99362567d5453f7fa6e227ec833
Copy to clipboard
Order (n)
0x1555555555555555555555555555553c6f2885259c31e3fcdf154624522d
Copy to clipboard
Cofactor (h)
0x6
Copy to clipboard

Representations

PEM

-----BEGIN EC PARAMETERS-----
BggqhkjOPQMADA==
-----END EC PARAMETERS-----
Download ecparam.pem
Copy to clipboard

PARI/GP

m = 239;
\\ reduction polynomial: z^239 + z^36 + 1
a = 0x4230017757a767fae42398569b746325d45313af0766266479b75654e65f;
b = 0x5037ea654196cff0cd82b2c14a2fcf2e3ff8775285b545722f03eacdb74b;
\\ curve: y^2 + x*y = x^3 + a*x^2 + b over GF(2^m)
G = [0x28f9d04e900069c8dc47a08534fe76d2b900b7d7ef31f5709f200c4ca205, 0x5667334c45aff3b5a03bad9dd75e2c71a99362567d5453f7fa6e227ec833];
n = 0x1555555555555555555555555555553c6f2885259c31e3fcdf154624522d;
h = 0x6;
Copy to clipboard

LaTeX

$\begin{aligned}
y^2 + x y &= x^3 + a x^2 + b \pmod{f(z)} \\
f(z) &= z^{239} + z^{36} + 1 \\
a &= 0x4230017757a767fae42398569b746325d45313af0766266479b75654e65f \\
b &= 0x5037ea654196cff0cd82b2c14a2fcf2e3ff8775285b545722f03eacdb74b \\
G &= (0x28f9d04e900069c8dc47a08534fe76d2b900b7d7ef31f5709f200c4ca205, 0x5667334c45aff3b5a03bad9dd75e2c71a99362567d5453f7fa6e227ec833) \\
n &= 0x1555555555555555555555555555553c6f2885259c31e3fcdf154624522d \\
h &= 0x6
\end{aligned}$
Copy to clipboard