The following provides additional security notes for your information regarding your Symantec Endpoint Encryption installation.This information applies to the client installations only.
If you enable the Workgroup Key feature in Removable Media Encryption, the effective key strength is limited to 128-bits, even when using AES 256-bit keys. This behavior occurs because the Workgroup Key feature uses the NIST P-256 ECC curve which only has 128-bits of effective strength.
Symantec Endpoint Encryption Drive Encryption uses 128-bit key strength despite using AES 256-bit keys. This is due to the Client Administrators' functionality leveraging the NIST P-256 ECC curve which has 128 bits of effective strength.