diff --git a/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl b/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl
index cafec70..fc703e9 100644
--- a/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl
+++ b/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl
@@ -87,12 +87,14 @@
  *        SHA-2 256.
  *      - Unpadded, RSAES-OAEP and RSAES-PKCS1-v1_5 padding modes for RSA encryption.
  *
- * o   ECDSA
+ * o   ECDSA and ECDH
  *
+ *      - IKeyMintDevices must support elliptic curve signing (Purpose::SIGN, Purpose::ATTEST_KEY)
+ *        and key agreement operations (Purpose::AGREE_KEY).
  *      - TRUSTED_ENVIRONMENT IKeyMintDevices must support NIST curves P-224, P-256, P-384 and
  *        P-521.  STRONGBOX IKeyMintDevices must support NIST curve P-256.
- *      - TRUSTED_ENVIRONMENT IKeyMintDevices must support SHA1, SHA-2 224, SHA-2 256, SHA-2
- *        384 and SHA-2 512 digest modes.  STRONGBOX IKeyMintDevices must support SHA-2 256.
+ *      - For signing, TRUSTED_ENVIRONMENT IKeyMintDevices must support SHA1, SHA-2 224, SHA-2 256,
+ *        SHA-2 384 and SHA-2 512 digest modes.  STRONGBOX IKeyMintDevices must support SHA-2 256.
  *      - TRUSTED_ENVRIONMENT IKeyMintDevices must support curve 25519 for Purpose::SIGN (Ed25519,
  *        as specified in RFC 8032), Purpose::ATTEST_KEY (Ed25519) or for KeyPurpose::AGREE_KEY
  *        (X25519, as specified in RFC 7748).  However, a key must have exactly one of these
@@ -302,12 +304,12 @@
      *   PaddingMode::RSA_OAEP, PaddingMode::RSA_PSS, PaddingMode::RSA_PKCS1_1_5_ENCRYPT and
      *   PaddingMode::RSA_PKCS1_1_5_SIGN for RSA keys.
      *
-     * == ECDSA Keys ==
+     * == ECDSA/ECDH Keys ==
      *
-     * Tag::EC_CURVE must be provided to generate an ECDSA key.  If it is not provided, generateKey
-     * must return ErrorCode::UNSUPPORTED_KEY_SIZE or ErrorCode::UNSUPPORTED_EC_CURVE. TEE
-     * IKeyMintDevice implementations must support all required curves.  StrongBox implementations
-     * must support P_256 and no other curves.
+     * Tag::EC_CURVE must be provided to generate an elliptic curve key.  If it is not provided,
+     * generateKey must return ErrorCode::UNSUPPORTED_KEY_SIZE or ErrorCode::UNSUPPORTED_EC_CURVE.
+     * TEE IKeyMintDevice implementations must support all required curves.  StrongBox
+     * implementations must support P_256 and no other curves.
      *
      * Tag::CERTIFICATE_NOT_BEFORE and Tag::CERTIFICATE_NOT_AFTER must be provided to specify the
      * valid date range for the returned X.509 certificate holding the public key. If omitted,
@@ -318,10 +320,10 @@
      * than one purpose should be rejected with ErrorCode::INCOMPATIBLE_PURPOSE.
      * StrongBox implementation do not support CURVE_25519.
      *
-     * Tag::DIGEST specifies digest algorithms that may be used with the new key.  TEE
-     * IKeyMintDevice implementations must support all Digest values (see Digest.aidl) for ECDSA
-     * keys; Ed25519 keys only support Digest::NONE. StrongBox IKeyMintDevice implementations must
-     * support SHA_2_256.
+     * Tag::DIGEST specifies digest algorithms that may be used with the new key when used for
+     * signing.  TEE IKeyMintDevice implementations must support all Digest values (see Digest.aidl)
+     * for ECDSA keys; Ed25519 keys only support Digest::NONE. StrongBox IKeyMintDevice
+     * implementations must support SHA_2_256.
      *
      * == AES Keys ==
      *