End User Encryption Key Protection Policy

Last Update Status: Updated January 2020

Overview

Encryption Key Management, if not done properly, can lead to compromise and disclosure of private keys use to secure sensitive data and hence, compromise of the data.   While users may understand it’s important to encryption certain documents and electronic communications, they may not be familiar with minimum standards for protection encryption keys.

Purpose

This policy outlines the requirements for protecting encryption keys that are under the control of end users. These requirements are designed to prevent unauthorized disclosure and subsequent fraudulent use. The protection methods outlined will include operational and technical controls, such as key backup procedures, encryption under a separate key and use of tamper-resistant hardware.

Policy

Secret Key Encryption Keys – Keys used for secret key encryption, also called symmetric cryptography, are protected as they are distributed to all parties that will use them. During distribution, the symmetric encryption keys must be encrypted using a stronger algorithm with a key of the longest key length for that algorithm. If the keys are for the strongest algorithm, then the key must be split, each portion of the key encrypted with a different key that is the longest key length authorized and the each encrypted portion is transmitted using different transmission mechanisms. The goal is to provide more stringent protection to the key than the data that is encrypted with that encryption key.

Symmetric encryption keys, when at rest, must be protected with security measures at least as stringent as the measures used for distribution of that key.

  • Public Key Encryption Keys

Public key cryptography, or asymmetric cryptography, uses public-private key pairs. The public key is passed to the certificate authority to be included in the digital certificate issued to the end user. The digital certificate is available to everyone once it issued. The private key should only be available to the end user to whom the corresponding digital certificate is issued.

The public-private key pairs used by the  public key infrastructure (PKI) are generated on the tamper-resistant smart card issued to an individual end user. The private key associated with an end user’s identity certificate, which are only used for digital signatures, will never leave the smart card. This prevents the Infosec Team from escrowing any private keys associated with identity certificates. The private key associated with any encryption certificates, which are used to encrypt email and other documents, must be escrowed in compliance with the company policies.