This java.security.spec.AlgorithmParameterSpec is a transparent representation of an initialization vector or IV. An IV is required for block ciphers used in feedback mode, such as DES in CBC mode.

Figure 17-21. javax.crypto.spec.IvParameterSpec

public class IvParameterSpec implements java.security.spec.AlgorithmParameterSpec {
// Public Constructors
     public IvParameterSpec(byte[ ] iv);  
     public IvParameterSpec(byte[ ] iv, int offset, int len);  
// Public Instance Methods
     public byte[ ] getIV( );  
}