crypto key zeroize rsa

Zero‑knowledge isn’t a magic bullet; if you leave private keys in RAM after a crash, an attacker with physical access can still dump them, so a proper zeroize routine is essential.

I’ve seen a lot of libs just memset the buffer, but the compiler can optimize that away – you need a volatile write or a dedicated API like SecureZeroMemory.

From a compliance angle, NIST SP 800‑57 explicitly requires key material to be overwritten before deallocation, so skipping zeroization could fail an audit. crypto key generate rsa

My hardware wallet does a full power‑cycle on exit; that’s the simplest way to guarantee the RSA key never lingers in volatile memory.

When I benchmarked OpenSSL’s RSA sign, the zero‑clear step added barely any overhead, so there’s no performance excuse to skip it.

If you’re writing Go code, use the crypto/subtle package’s ConstantTimeCopy to overwrite the slice; plain assignment won’t cut it.