diff --git a/security/rkp/aidl/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl b/security/rkp/aidl/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl
index c50666737c..ff710f14f6 100644
--- a/security/rkp/aidl/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl
+++ b/security/rkp/aidl/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl
@@ -222,7 +222,7 @@ interface IRemotelyProvisionedComponent {
      *                2 : bstr             ; KID : EEK ID
      *                3 : -25,             ; Algorithm : ECDH-ES + HKDF-256
      *                -1 : 4,              ; Curve : X25519
-     *                -2 : bstr            ; X25519 public key
+     *                -2 : bstr            ; X25519 public key, little-endian
      *            }
      *
      *            EekP256 = {              ; COSE_Key
@@ -440,6 +440,9 @@ interface IRemotelyProvisionedComponent {
      *
      * ; The following section defines some types that are reused throughout the above
      * ; data structures.
+     * ; NOTE: Integer encoding is different for Ed25519 and P256 keys:
+     * ;       - Ed25519 is LE: https://www.rfc-editor.org/rfc/rfc8032#section-3.1
+     * ;       - P256 is BE: https://www.secg.org/sec1-v2.pdf#page=19 (section 2.3.7)
      * PubKeyEd25519 = {                ; COSE_Key
      *     1 : 1,                       ; Key type : octet key pair
      *     3 : AlgorithmEdDSA,          ; Algorithm : EdDSA
@@ -451,8 +454,8 @@ interface IRemotelyProvisionedComponent {
      *     1 : 2,                       ; Key type : EC2
      *     3 : AlgorithmES256,          ; Algorithm : ECDSA w/ SHA-256
      *     -1 : 1,                      ; Curve: P256
-     *     -2 : bstr,                   ; X coordinate
-     *     -3 : bstr                    ; Y coordinate
+     *     -2 : bstr,                   ; X coordinate, big-endian
+     *     -3 : bstr                    ; Y coordinate, big-endian
      * }
      *
      * AlgorithmES256 = -7
diff --git a/security/rkp/aidl/android/hardware/security/keymint/MacedPublicKey.aidl b/security/rkp/aidl/android/hardware/security/keymint/MacedPublicKey.aidl
index 275e322784..1e41d1b98c 100644
--- a/security/rkp/aidl/android/hardware/security/keymint/MacedPublicKey.aidl
+++ b/security/rkp/aidl/android/hardware/security/keymint/MacedPublicKey.aidl
@@ -36,12 +36,15 @@ parcelable MacedPublicKey {
      *     ]
      *
      *     ; NOTE: -70000 is deprecated for v3 HAL implementations.
+     *     ; NOTE: Integer encoding is different for Ed25519 and P256 keys:
+     *     ;       - Ed25519 is LE: https://www.rfc-editor.org/rfc/rfc8032#section-3.1
+     *     ;       - P256 is BE: https://www.secg.org/sec1-v2.pdf#page=19 (section 2.3.7)
      *     PublicKey = {               ; COSE_Key
      *         1 : 2,                  ; Key type : EC2
      *         3 : -7,                 ; Algorithm : ES256
      *         -1 : 1,                 ; Curve : P256
-     *         -2 : bstr,              ; X coordinate, little-endian
-     *         -3 : bstr,              ; Y coordinate, little-endian
+     *         -2 : bstr,              ; X coordinate, big-endian
+     *         -3 : bstr,              ; Y coordinate, big-endian
      *         -70000 : nil            ; Presence indicates this is a test key. If set, K_mac is
      *                                 ; all zeros.
      *     },
diff --git a/security/rkp/aidl/android/hardware/security/keymint/ProtectedData.aidl b/security/rkp/aidl/android/hardware/security/keymint/ProtectedData.aidl
index d59508b962..3f699bc75a 100644
--- a/security/rkp/aidl/android/hardware/security/keymint/ProtectedData.aidl
+++ b/security/rkp/aidl/android/hardware/security/keymint/ProtectedData.aidl
@@ -209,7 +209,7 @@ parcelable ProtectedData {
      *     PubKeyX25519 = {                 ; COSE_Key
      *          1 : 1,                      ; Key type : Octet Key Pair
      *         -1 : 4,                      ; Curve : X25519
-     *         -2 : bstr                    ; Sender X25519 public key
+     *         -2 : bstr                    ; Sender X25519 public key, little-endian
      *     }
      *
      *     PubKeyEd25519 = {                ; COSE_Key
@@ -222,16 +222,16 @@ parcelable ProtectedData {
      *     PubKeyEcdhP256 = {               ; COSE_Key
      *          1 : 2,                      ; Key type : EC2
      *          -1 : 1,                     ; Curve : P256
-     *          -2 : bstr                   ; Sender X coordinate
-     *          -3 : bstr                   ; Sender Y coordinate
+     *          -2 : bstr                   ; Sender X coordinate, big-endian
+     *          -3 : bstr                   ; Sender Y coordinate, big-endian
      *     }
      *
      *     PubKeyECDSA256 = {               ; COSE_Key
      *         1 : 2,                       ; Key type : EC2
      *         3 : AlgorithmES256,          ; Algorithm : ECDSA w/ SHA-256
      *         -1 : 1,                      ; Curve: P256
-     *         -2 : bstr,                   ; X coordinate
-     *         -3 : bstr                    ; Y coordinate
+     *         -2 : bstr,                   ; X coordinate, big-endian
+     *         -3 : bstr                    ; Y coordinate, big-endian
      *     }
      *
      *     AlgorithmES256 = -7