The Schnorr signature patent that expired in 2008? The one-bit-sign point compression patent that expired earlier this year? The algorithms in RFC6090 which would be too old for patents anyway?
While there were (and are) some specific implementation techniques for efficient ECC covered by patents, many of them have now expired, and many others have better patent-free alternatives anyway.
While there were (and are) some specific implementation techniques for efficient ECC covered by patents, many of them have now expired, and many others have better patent-free alternatives anyway.