diff --git a/17.md b/17.md
index ebf36f06..59d47f1e 100644
--- a/17.md
+++ b/17.md
@@ -25,39 +25,60 @@ Following [NIP-59](59.md), the **unsigned** chat messages must be sealed (`kind:
 ```js
 {
   "id": "<usual hash>",
-  "pubkey": wrapperPublicKey,
+  "pubkey": wrapperKey.public,
   "created_at": randomTimeUpTo2DaysInThePast,
   "kind": 1059, // gift wrap
   "tags": [
-    ["p", receiverPublicKey, "<relay-url>"] // receiver
+    ["p", receiverIdentityKey.public, "<relay-url>"] // receiver
   ],
   "content": nip44.encrypt(
     {
       "id": "<usual hash>",
-      "pubkey": senderPublicKey,
+      "pubkey": senderIdentityKey.public,
       "created_at": randomTimeUpTo2DaysInThePast,
       "kind": 13, // seal
       "tags": [], // no tags
       "content": nip44.encrypt(
         unsignedMessageRumor,
-        nip44.compute_conversation_key(senderPrivateKey, receiverPublicKey)
+        nip44.compute_conversation_key(senderEncryptionKey.private, receiverEncryptionKey.public)
       ),
-      "sig": "<signed by senderPrivateKey>"
+      "sig": "<signed by senderIdentity.private>"
     },
-    nip44.compute_conversation_key(wrapperPrivateKey, receiverPublicKey)
+    nip44.compute_conversation_key(wrapperKey.private, receiverEncryptionKey.public)
   ),
-  "sig": "<signed by randomPrivateKey>"
+  "sig": "<signed by wrapperKey.private>"
 }
 ```
 
 `unsignedMessageRumor` is a rumor (an unsigned event, as per [NIP-59](59.md)), usually a `kind:14`, but could also be a different kind, see [Message Rumor Definitions](#message-rumor-definitions) below.
 
-`wrapperPrivateKey` and `wrappedPublicKey` are a new keypair, generated randomly anew for each message sent.
+`wrapperKey` is a new keypair, generated randomly anew for each message sent.
 
 Clients MUST verify if pubkey of the `kind:13` is the same pubkey as that of the `unsignedMessageRumor`, otherwise any sender can impersonate any other by simply changing the pubkey on the rumor.
 
 Clients SHOULD randomize `created_at` in up to two days in the past in both the seal and the gift wrap to make sure grouping by `created_at` doesn't reveal any metadata.
 
+### Encryption Keys
+
+There is a difference between the keypairs used in `nip44.compute_conversation_key()` ("encryption key") and those used to sign the seal event ("identity key").
+
+By default, these keypairs are the same, i.e. `receiverEncryptionKey == receiverIdentityKey` and `senderIdentityKey == senderEncryptionKey`, but when an event `kind:10044` is present that changes things:
+
+```js
+{
+  "kind": 10044,
+  "pubkey": receiverIdentityKey.public,
+  "tags": [
+    ["n", receiverEncryptionKey.public]
+  ],
+  // other fields...
+}
+```
+
+The existence of this event shows that the receiver wants to receive messages encrypted to a different key, so the sender should use that when calling `nip44.compute_conversation_key()` (both during encryption and decryption).
+
+When sending, `p`-tagging the receiver should still use their _identity key_; and when receiving messages the receiver should still assume the `"author"` field of the seal event contains the _identity key_.
+
 ## Publishing
 
 Kind `10050` indicates the user's preferred relays to receive DMs. The event MUST include a list of `relay` tags with relay URIs.
@@ -69,7 +90,6 @@ Kind `10050` indicates the user's preferred relays to receive DMs. The event MUS
     ["relay", "wss://inbox.nostr.wine"],
     ["relay", "wss://myrelay.nostr1.com"],
   ],
-  "content": "",
   // other fields...
 }
 ```