diff --git a/Libraries/LibWeb/Crypto/CryptoAlgorithms.cpp b/Libraries/LibWeb/Crypto/CryptoAlgorithms.cpp
index 0e59ce8c04d..5fcb21c8433 100644
--- a/Libraries/LibWeb/Crypto/CryptoAlgorithms.cpp
+++ b/Libraries/LibWeb/Crypto/CryptoAlgorithms.cpp
@@ -274,6 +274,32 @@ static WebIDL::ExceptionOr<ByteBuffer> generate_random_key(JS::VM& vm, u16 const
     return key_buffer;
 }
 
+JS::ThrowCompletionOr<GC::Ref<JS::Object>> EncapsulatedKey::to_object(JS::Realm& realm)
+{
+    auto object = JS::Object::create(realm, realm.intrinsics().object_prototype());
+
+    if (shared_key.has_value())
+        TRY(object->create_data_property("shared_key"_utf16_fly_string, shared_key.value()));
+
+    if (ciphertext.has_value())
+        TRY(object->create_data_property("ciphertext"_utf16_fly_string, JS::ArrayBuffer::create(realm, ciphertext.value())));
+
+    return object;
+}
+
+JS::ThrowCompletionOr<GC::Ref<JS::Object>> EncapsulatedBits::to_object(JS::Realm& realm)
+{
+    auto object = JS::Object::create(realm, realm.intrinsics().object_prototype());
+
+    if (shared_key.has_value())
+        TRY(object->create_data_property("shared_key"_utf16_fly_string, JS::ArrayBuffer::create(realm, shared_key.value())));
+
+    if (ciphertext.has_value())
+        TRY(object->create_data_property("ciphertext"_utf16_fly_string, JS::ArrayBuffer::create(realm, ciphertext.value())));
+
+    return object;
+}
+
 AlgorithmParams::~AlgorithmParams() = default;
 
 JS::ThrowCompletionOr<NonnullOwnPtr<AlgorithmParams>> AlgorithmParams::from_value(JS::VM&, JS::Value)
diff --git a/Libraries/LibWeb/Crypto/CryptoAlgorithms.h b/Libraries/LibWeb/Crypto/CryptoAlgorithms.h
index cbdd8fd992b..7a1c4dda8fc 100644
--- a/Libraries/LibWeb/Crypto/CryptoAlgorithms.h
+++ b/Libraries/LibWeb/Crypto/CryptoAlgorithms.h
@@ -26,6 +26,22 @@ using AlgorithmIdentifier = Variant<GC::Root<JS::Object>, String>;
 using NamedCurve = String;
 using KeyDataType = Variant<GC::Root<WebIDL::BufferSource>, Bindings::JsonWebKey>;
 
+// https://wicg.github.io/webcrypto-modern-algos/#encapsulation
+struct EncapsulatedKey {
+    Optional<GC::Root<CryptoKey>> shared_key;
+    Optional<ByteBuffer> ciphertext;
+
+    JS::ThrowCompletionOr<GC::Ref<JS::Object>> to_object(JS::Realm&);
+};
+
+// https://wicg.github.io/webcrypto-modern-algos/#encapsulation
+struct EncapsulatedBits {
+    Optional<ByteBuffer> shared_key;
+    Optional<ByteBuffer> ciphertext;
+
+    JS::ThrowCompletionOr<GC::Ref<JS::Object>> to_object(JS::Realm&);
+};
+
 struct HashAlgorithmIdentifier : public AlgorithmIdentifier {
     using AlgorithmIdentifier::AlgorithmIdentifier;
 
diff --git a/Libraries/LibWeb/Crypto/SubtleCrypto.idl b/Libraries/LibWeb/Crypto/SubtleCrypto.idl
index 550c4b2acab..4950d700209 100644
--- a/Libraries/LibWeb/Crypto/SubtleCrypto.idl
+++ b/Libraries/LibWeb/Crypto/SubtleCrypto.idl
@@ -42,6 +42,18 @@ dictionary JsonWebKey {
     DOMString k;
 };
 
+// https://wicg.github.io/webcrypto-modern-algos/#encapsulation
+dictionary EncapsulatedKey {
+    CryptoKey sharedKey;
+    ArrayBuffer ciphertext;
+};
+
+// https://wicg.github.io/webcrypto-modern-algos/#encapsulation
+dictionary EncapsulatedBits {
+    ArrayBuffer sharedKey;
+    ArrayBuffer ciphertext;
+};
+
 // https://w3c.github.io/webcrypto/#subtlecrypto-interface
 [SecureContext,Exposed=(Window,Worker)]
 interface SubtleCrypto {