Server Features » TLS Key exchange group » P-521

TLS Key exchange group: P-521

Percentage of IRC SSL/TLS servers with key exchange Elliptic Curve Diffie-Hellman (ECDH) using P-521 (secp521r1).
Showing percentages by IRC server software.

About this test result: Elliptic Curve Diffie-Hellman (ECDH) using P-521 curve (also called secp521r1).
This ECDH with classic cryptography is widely used today. However, it is not a PQC algorithm, so is vulnerable to Harvest now, decrypt later.

Table

Percentage of IRC SSL/TLS servers with key exchange Elliptic Curve Diffie-Hellman (ECDH) using P-521 (secp521r1).
Showing percentages by IRC server software.
Software Dec 2025
charybdis 70%
Hybrid 4%
InspIRCd 3%
Solanum 1%
UnrealIRCd 40%
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