2) Non-strict DER ECDSA signatures (lax OpenSSL encodings) …

79b · February 13, 2026

2) Non-strict DER ECDSA signatures (lax OpenSSL encodings)
- Example: A signature with extra leading zeroes or otherwise not strict-DER, which OpenSSL’s legacy parser would still accept pre-BIP66.
- Early Bitcoin: Valid (OpenSSL’s permissive parser accepted many encodings).
- BTC today: Invalid (BIP66 makes strict DER a consensus rule).
- BCH today: Invalid (BCH inherited strict DER from BTC pre-fork and kept it).
- BSV today: Invalid (BSV has not removed strict DER at the consensus layer for normal transactions).