diff --git a/KeyUtil.cpp b/KeyUtil.cpp
index c1a82fb..f822377 100644
--- a/KeyUtil.cpp
+++ b/KeyUtil.cpp
@@ -163,28 +163,80 @@
     return true;
 }
 
+// Build a struct fscrypt_key_specifier for use in the key management ioctls.
+static bool buildKeySpecifier(fscrypt_key_specifier* spec, const std::string& raw_ref,
+                              int policy_version) {
+    switch (policy_version) {
+        case 1:
+            if (raw_ref.size() != FSCRYPT_KEY_DESCRIPTOR_SIZE) {
+                LOG(ERROR) << "Invalid key specifier size for v1 encryption policy: "
+                           << raw_ref.size();
+                return false;
+            }
+            spec->type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
+            memcpy(spec->u.descriptor, raw_ref.c_str(), FSCRYPT_KEY_DESCRIPTOR_SIZE);
+            return true;
+        case 2:
+            if (raw_ref.size() != FSCRYPT_KEY_IDENTIFIER_SIZE) {
+                LOG(ERROR) << "Invalid key specifier size for v2 encryption policy: "
+                           << raw_ref.size();
+                return false;
+            }
+            spec->type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER;
+            memcpy(spec->u.identifier, raw_ref.c_str(), FSCRYPT_KEY_IDENTIFIER_SIZE);
+            return true;
+        default:
+            LOG(ERROR) << "Invalid encryption policy version: " << policy_version;
+            return false;
+    }
+}
+
 // Install a file-based encryption key to the kernel, for use by encrypted files
-// on the specified filesystem.
+// on the specified filesystem using the specified encryption policy version.
 //
-// We use FS_IOC_ADD_ENCRYPTION_KEY if the kernel supports it.  Otherwise we add
-// the key to the legacy global session keyring.
+// For v1 policies, we use FS_IOC_ADD_ENCRYPTION_KEY if the kernel supports it.
+// Otherwise we add the key to the legacy global session keyring.
+//
+// For v2 policies, we always use FS_IOC_ADD_ENCRYPTION_KEY; it's the only way
+// the kernel supports.
 //
 // Returns %true on success, %false on failure.  On success also sets *raw_ref
 // to the raw key reference for use in the encryption policy.
-bool installKey(const KeyBuffer& key, const std::string& mountpoint, std::string* raw_ref) {
-    *raw_ref = generateKeyRef((const uint8_t*)key.data(), key.size());
-    if (!isFsKeyringSupported()) {
-        return installKeyLegacy(key, *raw_ref);
-    }
-
+bool installKey(const KeyBuffer& key, const std::string& mountpoint, int policy_version,
+                std::string* raw_ref) {
     // Put the fscrypt_add_key_arg in an automatically-zeroing buffer, since we
     // have to copy the raw key into it.
     KeyBuffer arg_buf(sizeof(struct fscrypt_add_key_arg) + key.size(), 0);
     struct fscrypt_add_key_arg* arg = (struct fscrypt_add_key_arg*)arg_buf.data();
 
-    arg->key_spec.type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
-    memcpy(arg->key_spec.u.descriptor, raw_ref.c_str(), FSCRYPT_KEY_DESCRIPTOR_SIZE);
+    // Initialize the "key specifier", which is like a name for the key.
+    switch (policy_version) {
+        case 1:
+            // A key for a v1 policy is specified by an arbitrary 8-byte
+            // "descriptor", which must be provided by userspace.  We use the
+            // first 8 bytes from the double SHA-512 of the key itself.
+            *raw_ref = generateKeyRef((const uint8_t*)key.data(), key.size());
+            if (!isFsKeyringSupported()) {
+                return installKeyLegacy(key, *raw_ref);
+            }
+            if (!buildKeySpecifier(&arg->key_spec, *raw_ref, policy_version)) {
+                return false;
+            }
+            break;
+        case 2:
+            // A key for a v2 policy is specified by an 16-byte "identifier",
+            // which is a cryptographic hash of the key itself which the kernel
+            // computes and returns.  Any user-provided value is ignored; we
+            // just need to set the specifier type to indicate that we're adding
+            // this type of key.
+            arg->key_spec.type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER;
+            break;
+        default:
+            LOG(ERROR) << "Invalid encryption policy version: " << policy_version;
+            return false;
+    }
 
+    // Provide the raw key.
     arg->raw_size = key.size();
     memcpy(arg->raw, key.data(), key.size());
 
@@ -195,11 +247,14 @@
     }
 
     if (ioctl(fd, FS_IOC_ADD_ENCRYPTION_KEY, arg) != 0) {
-        PLOG(ERROR) << "Failed to install fscrypt key with ref " << keyrefstring(*raw_ref) << " to "
-                    << mountpoint;
+        PLOG(ERROR) << "Failed to install fscrypt key to " << mountpoint;
         return false;
     }
 
+    if (arg->key_spec.type == FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER) {
+        // Retrieve the key identifier that the kernel computed.
+        *raw_ref = std::string((char*)arg->key_spec.u.identifier, FSCRYPT_KEY_IDENTIFIER_SIZE);
+    }
     LOG(DEBUG) << "Installed fscrypt key with ref " << keyrefstring(*raw_ref) << " to "
                << mountpoint;
     return true;
@@ -234,8 +289,8 @@
 // remove the key from the legacy global session keyring.
 //
 // In the latter case, the caller is responsible for dropping caches.
-bool evictKey(const std::string& mountpoint, const std::string& raw_ref) {
-    if (!isFsKeyringSupported()) {
+bool evictKey(const std::string& mountpoint, const std::string& raw_ref, int policy_version) {
+    if (policy_version == 1 && !isFsKeyringSupported()) {
         return evictKeyLegacy(raw_ref);
     }
 
@@ -248,8 +303,9 @@
     struct fscrypt_remove_key_arg arg;
     memset(&arg, 0, sizeof(arg));
 
-    arg.key_spec.type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
-    memcpy(arg.key_spec.u.descriptor, raw_ref.c_str(), FSCRYPT_KEY_DESCRIPTOR_SIZE);
+    if (!buildKeySpecifier(&arg.key_spec, raw_ref, policy_version)) {
+        return false;
+    }
 
     std::string ref = keyrefstring(raw_ref);
 
@@ -271,7 +327,8 @@
 
 bool retrieveAndInstallKey(bool create_if_absent, const KeyAuthentication& key_authentication,
                            const std::string& key_path, const std::string& tmp_path,
-                           const std::string& volume_uuid, std::string* key_ref) {
+                           const std::string& volume_uuid, int policy_version,
+                           std::string* key_ref) {
     KeyBuffer key;
     if (pathExists(key_path)) {
         LOG(DEBUG) << "Key exists, using: " << key_path;
@@ -286,7 +343,7 @@
         if (!storeKeyAtomically(key_path, tmp_path, key_authentication, key)) return false;
     }
 
-    if (!installKey(key, BuildDataPath(volume_uuid), key_ref)) {
+    if (!installKey(key, BuildDataPath(volume_uuid), policy_version, key_ref)) {
         LOG(ERROR) << "Failed to install key in " << key_path;
         return false;
     }