text: **12.4 Enabling encryption**
  
  This section describes the process to create and store system master access key copies, 
  also referred to as*encryption keys*. These keys can be stored on any or both of two key 
  providers: USB flash drives or a key server. 
  
  Two types of key servers are supported by IBM Spectrum Virtualize: 
  
  (cid:2) IBM Security Key Lifecycle Manager (SKLM), introduced in IBM Spectrum Virtualize V7.8. 
  (cid:2) Gemalto SafeNet KeySecure, introduced in IBM Spectrum Virtualize V8.2. 
  
  IBM Spectrum Virtualize code V8.1 introduced the ability to define up to four encryption key 
  servers, which is a preferred configuration because it increases key provider availability. In 
  this version, support for simultaneous use of both USB flash drives and key server was 
  added. 
  
  Organizations that use encryption key management servers might consider parallel use of 
  USB flash drives as a backup solution. During normal operation, such drives can be 
  disconnected and stored in a secure location. However, during a catastrophic loss of 
  encryption servers, the USB drives can still be used to unlock the encrypted storage. 
  
  The key server and USB flash drive characteristics that are described next might help you to 
  choose the type of encryption key provider that you want to use. 