sect163r2 (NIST B-163) is a pseudo-random curve over the binary field GF(2^163); NIST has deprecated it.
sect163r2 is a binary Weierstrass curve y² + xy = x³ + ax² + b over the binary field GF(2^163) with a 163-bit prime-order subgroup and cofactor 2; its estimated security level is 80 bits. Status: deprecated, do not use for new keys.
sect163r2 is y² + xy = x³ + x² + b over GF(2^163) with the reduction polynomial f shown above; b was derived from the listed seed with SHA-1 (ANSI X9.62). The group has cofactor 2 and about 80 bits of security.
FIPS 186-2 to 186-4 listed it as B-163. NIST SP 800-186 (2023) deprecates every curve over a binary field, and RFC 8422 deprecated them for TLS. At about 80 bits of security it is also below the 112-bit minimum, so NIST treats it as legacy-use only. OpenSSL can be built without binary-curve support (no-ec2m).