Dell Configuration Guide for the S4048–ON System 9.14.2.4

Removing the RSA Host Keys and Zeroizing Storage

Use the crypto key zeroize rsa command to delete the host key pairs, both the public and private key information for RSA 1 and or RSA 2 types. Note that when FIPS mode is enabled there is no RSA 1 key pair. Any memory currently holding these keys is zeroized (written over with zeroes) and the NVRAM location where the keys are stored for persistence across reboots is also zeroized. 

To remove the generated RSA host keys and zeroize the key storage location, use the crypto key zeroize rsa command in CONFIGURATION mode. 

DellEMC(conf)#crypto key zeroize rsa