When you find out that Bitcoin-Core devs just learned about memset being "insecure" by most compilers by default. 

https://github.com/bitcoin-core/secp256k1/compare/v0.5.1...v0.6.0

Noscrypt has used platform "secure" memset since it's inception:
https://git.vaughnnugent.com/cgit/vnuge/noscrypt.git/tree/src/nc-crypto.c#n197