<div class="content" name="EFS_KEY_INFO" uuid="49a8335f-3136-4059-9deb-9574d5ed5c86"><p>The EFS_KEY_INFO type is used to represent information about
a <a href="230807ac-20be-494f-86e3-4c8ac23ea584#gt_718bfd46-3cd2-45e8-befa-55f5c9f3be7b" data-linktype="relative-path">key</a> of a symmetric
cryptosystem.</p><dl>
<dd>
<div><pre> typedef struct {
   DWORD dwVersion;
   unsigned long Entropy;
   ALG_ID Algorithm;
   unsigned long KeyLength;
 } EFS_KEY_INFO;
</pre></div>
</dd></dl><p><b>dwVersion:</b>  The version of this data
structure. It MUST be equal to 0x00000001.</p><p><b>Entropy:</b>  The actual number of bits
of entropy or true randomness in the key. This value, divided by 8, MUST be
less than or equal to the value of the <b>KeyLength</b> member.</p><p><b>Algorithm:</b>  The cryptographic
algorithm with which the key is intended to be used.</p><p><b>KeyLength:</b>  The total length, in
bytes, of the key. This value, multiplied by 8, MUST be greater than or equal
to the value of the <b>Entropy</b> member. Valid combinations of Entropy,
Algorithm, and KeyLength are specified in section <a href="4cc8e6ae-99aa-483e-99c1-ab4c0ee46294" data-linktype="relative-path">2.2.13</a>.</p></div>