diff --git a/keyserver/addons/rust-node-addon/src/identity_client/mod.rs b/keyserver/addons/rust-node-addon/src/identity_client/mod.rs
--- a/keyserver/addons/rust-node-addon/src/identity_client/mod.rs
+++ b/keyserver/addons/rust-node-addon/src/identity_client/mod.rs
@@ -4,6 +4,7 @@
 pub mod identity {
   tonic::include_proto!("identity");
 }
+pub mod update_user;
 
 use comm_opaque::Cipher;
 use identity::identity_service_client::IdentityServiceClient;
diff --git a/keyserver/addons/rust-node-addon/src/identity_client/update_user.rs b/keyserver/addons/rust-node-addon/src/identity_client/update_user.rs
new file mode 100644
--- /dev/null
+++ b/keyserver/addons/rust-node-addon/src/identity_client/update_user.rs
@@ -0,0 +1,312 @@
+use crate::identity_client::identity as proto;
+use crate::identity_client::identity::identity_service_client::IdentityServiceClient;
+use crate::identity_client::identity::pake_login_response::Data::AccessToken;
+use crate::identity_client::identity::{
+  update_user_request, update_user_response, UpdateUserRequest,
+  UpdateUserResponse,
+};
+use crate::identity_client::{AUTH_TOKEN, IDENTITY_SERVICE_SOCKET_ADDR};
+use comm_opaque::Cipher;
+use napi::bindgen_prelude::*;
+use opaque_ke::{
+  ClientLogin, ClientLoginFinishParameters, ClientLoginStartParameters,
+  ClientLoginStartResult, ClientRegistration,
+  ClientRegistrationFinishParameters, CredentialFinalization,
+  CredentialResponse, RegistrationUpload,
+};
+use rand::{rngs::OsRng, CryptoRng, Rng};
+use tokio::sync::mpsc;
+use tokio_stream::wrappers::ReceiverStream;
+use tonic;
+use tonic::{metadata::MetadataValue, transport::Channel};
+use tracing::{error, instrument};
+
+#[napi]
+#[instrument(skip_all)]
+pub async fn update_user(user_id: String, password: String) -> Result<String> {
+  let channel = Channel::from_static(&IDENTITY_SERVICE_SOCKET_ADDR)
+    .connect()
+    .await
+    .map_err(|_| Error::from_status(Status::GenericFailure))?;
+  let token: MetadataValue<_> = AUTH_TOKEN
+    .parse()
+    .map_err(|_| Error::from_status(Status::GenericFailure))?;
+  let mut identity_client = IdentityServiceClient::with_interceptor(
+    channel,
+    |mut req: tonic::Request<()>| {
+      req.metadata_mut().insert("authorization", token.clone());
+      Ok(req)
+    },
+  );
+
+  // Create a RegistrationRequest channel and use ReceiverStream to turn the
+  // MPSC receiver into a Stream for outbound messages
+  let (tx, rx) = mpsc::channel(1);
+  let stream = ReceiverStream::new(rx);
+  let request = tonic::Request::new(stream);
+
+  // `response` is the Stream for inbound messages
+  let mut response = identity_client
+    .update_user(request)
+    .await
+    .map_err(|e| Error::new(Status::GenericFailure, e.to_string()))?
+    .into_inner();
+
+  // Start PAKE registration on client and send initial registration request
+  // to Identity service
+  let mut client_rng = OsRng;
+  let (registration_request, client_registration) =
+    pake_registration_start(&mut client_rng, user_id, &password)?;
+  send_to_mpsc(&tx, registration_request).await?;
+
+  // Handle responses from Identity service sequentially, making sure we get
+  // messages in the correct order
+
+  // Finish PAKE registration and begin PAKE login; send the final
+  // registration request and initial login request together to reduce the
+  // number of trips
+  let message = response
+    .message()
+    .await
+    .map_err(|e| Error::new(Status::GenericFailure, e.to_string()))?;
+  let registration_response = get_registration_response(message)?;
+  let client_login = handle_registration_response(
+    &registration_response,
+    &mut client_rng,
+    client_registration,
+    &password,
+    &tx,
+  )
+  .await?;
+
+  // Finish PAKE login; send final login request to Identity service
+  let message = response
+    .message()
+    .await
+    .map_err(|e| Error::new(Status::GenericFailure, e.to_string()))?;
+  let credential_response = get_login_credential_response(message)?;
+  handle_login_credential_response(&credential_response, client_login, &tx)
+    .await
+    .map_err(|e| Error::new(Status::GenericFailure, e.to_string()))?;
+
+  // Return access token
+  let message = response
+    .message()
+    .await
+    .map_err(|e| Error::new(Status::GenericFailure, e.to_string()))?;
+  get_login_token_response(message)
+}
+
+fn handle_unexpected_response<T: std::fmt::Debug>(message: Option<T>) -> Error {
+  error!("Received an unexpected message: {:?}", message);
+  Error::from_status(Status::GenericFailure)
+}
+
+async fn send_to_mpsc<T>(tx: &mpsc::Sender<T>, request: T) -> Result<()> {
+  if let Err(e) = tx.send(request).await {
+    error!("Response was dropped: {}", e);
+    return Err(Error::from_status(Status::GenericFailure));
+  }
+  Ok(())
+}
+
+fn pake_login_start(
+  rng: &mut (impl Rng + CryptoRng),
+  password: &str,
+) -> Result<ClientLoginStartResult<Cipher>> {
+  ClientLogin::<Cipher>::start(
+    rng,
+    password.as_bytes(),
+    ClientLoginStartParameters::default(),
+  )
+  .map_err(|e| {
+    error!("Failed to start PAKE login: {}", e);
+    Error::from_status(Status::GenericFailure)
+  })
+}
+
+fn pake_login_finish(
+  credential_response_bytes: &[u8],
+  client_login: ClientLogin<Cipher>,
+) -> Result<CredentialFinalization<Cipher>> {
+  client_login
+    .finish(
+      CredentialResponse::deserialize(credential_response_bytes).map_err(
+        |e| {
+          error!("Could not deserialize credential response bytes: {}", e);
+          Error::from_status(Status::GenericFailure)
+        },
+      )?,
+      ClientLoginFinishParameters::default(),
+    )
+    .map_err(|e| {
+      error!("Failed to finish PAKE login: {}", e);
+      Error::from_status(Status::GenericFailure)
+    })
+    .map(|res| res.message)
+}
+
+fn pake_registration_start(
+  rng: &mut (impl Rng + CryptoRng),
+  user_id: String,
+  password: &str,
+) -> Result<(UpdateUserRequest, ClientRegistration<Cipher>)> {
+  let client_registration_start_result =
+    ClientRegistration::<Cipher>::start(rng, password.as_bytes()).map_err(
+      |e| {
+        error!("Failed to start PAKE registration: {}", e);
+        Error::from_status(Status::GenericFailure)
+      },
+    )?;
+  let pake_registration_request =
+    client_registration_start_result.message.serialize();
+  Ok((
+    UpdateUserRequest {
+      data: Some(update_user_request::Data::Request(
+        crate::identity_client::identity::PakeRegistrationRequestAndUserId {
+          user_id,
+          pake_registration_request,
+          username: "placeholder-username".to_string(),
+          signing_public_key: "placeholder-signing-public-key".to_string(),
+          session_initialization_info: None,
+        },
+      )),
+    },
+    client_registration_start_result.state,
+  ))
+}
+
+async fn handle_registration_response(
+  registration_reponse_payload: &[u8],
+  client_rng: &mut (impl Rng + CryptoRng),
+  client_registration: ClientRegistration<Cipher>,
+  password: &str,
+  tx: &mpsc::Sender<UpdateUserRequest>,
+) -> Result<ClientLogin<Cipher>> {
+  let pake_registration_upload = pake_registration_finish(
+    client_rng,
+    &registration_reponse_payload,
+    client_registration,
+  )?
+  .serialize();
+  let client_login_start_result = pake_login_start(client_rng, password)?;
+  let pake_login_request =
+    client_login_start_result.message.serialize().map_err(|e| {
+      error!("Could not serialize credential request: {}", e);
+      Error::from_status(Status::GenericFailure)
+    })?;
+
+  // `registration_request` is a gRPC message containing serialized bytes to
+  // complete PAKE registration and begin PAKE login
+  let inner_message: update_user_request::Data =
+    update_user_request::Data::PakeRegistrationUploadAndCredentialRequest(
+      crate::identity_client::identity::PakeRegistrationUploadAndCredentialRequest {
+        pake_registration_upload,
+        pake_credential_request: pake_login_request,
+      },
+    );
+  let registration_request = UpdateUserRequest {
+    data: Some(inner_message),
+  };
+  send_to_mpsc(tx, registration_request).await?;
+  Ok(client_login_start_result.state)
+}
+
+fn get_registration_response(
+  message: Option<UpdateUserResponse>,
+) -> Result<Vec<u8>> {
+  match message {
+    Some(UpdateUserResponse {
+      data:
+        Some(update_user_response::Data::PakeRegistrationResponse(
+          registration_response_bytes,
+        )),
+      ..
+    }) => Ok(registration_response_bytes),
+    _ => {
+      error!("Received an unexpected message: {:?}", message);
+      Err(Error::from_status(Status::GenericFailure))
+    }
+  }
+}
+
+async fn handle_login_credential_response(
+  registration_response_payload: &[u8],
+  client_login: ClientLogin<Cipher>,
+  tx: &mpsc::Sender<UpdateUserRequest>,
+) -> Result<()> {
+  let pake_login_finish_result =
+    pake_login_finish(&registration_response_payload, client_login)?;
+  let login_finish_message =
+    pake_login_finish_result.serialize().map_err(|e| {
+      error!("Could not serialize credential request: {}", e);
+      Error::from_status(Status::GenericFailure)
+    })?;
+  let registration_request = UpdateUserRequest {
+    data: Some(
+      proto::update_user_request::Data::PakeLoginFinalizationMessage(
+        login_finish_message,
+      ),
+    ),
+  };
+  send_to_mpsc(tx, registration_request).await
+}
+
+fn get_login_credential_response(
+  message: Option<UpdateUserResponse>,
+) -> Result<Vec<u8>> {
+  match message {
+    Some(UpdateUserResponse {
+      data:
+        Some(update_user_response::Data::PakeLoginResponse(
+          proto::PakeLoginResponse {
+            data:
+              Some(proto::pake_login_response::Data::PakeCredentialResponse(
+                bytes,
+              )),
+          },
+        )),
+    }) => Ok(bytes),
+    _ => Err(handle_unexpected_response(message)),
+  }
+}
+
+fn get_login_token_response(
+  message: Option<UpdateUserResponse>,
+) -> Result<String> {
+  match message {
+    Some(UpdateUserResponse {
+      data:
+        Some(update_user_response::Data::PakeLoginResponse(
+          proto::PakeLoginResponse {
+            data: Some(AccessToken(access_token)),
+          },
+        )),
+    }) => Ok(access_token),
+    _ => Err(handle_unexpected_response(message)),
+  }
+}
+
+fn pake_registration_finish(
+  rng: &mut (impl Rng + CryptoRng),
+  registration_response_bytes: &[u8],
+  client_registration: ClientRegistration<Cipher>,
+) -> Result<RegistrationUpload<Cipher>> {
+  let register_payload =
+    opaque_ke::RegistrationResponse::deserialize(registration_response_bytes)
+      .map_err(|e| {
+      error!("Could not deserialize registration response bytes: {}", e);
+      Error::from_status(Status::GenericFailure)
+    })?;
+  client_registration
+    .finish(
+      rng,
+      register_payload,
+      ClientRegistrationFinishParameters::default(),
+    )
+    .map_err(|e| {
+      error!("Failed to finish PAKE registration: {}", e);
+      Error::from_status(Status::GenericFailure)
+    })
+    .map(|res| res.message)
+}
diff --git a/keyserver/src/updaters/account-updaters.js b/keyserver/src/updaters/account-updaters.js
--- a/keyserver/src/updaters/account-updaters.js
+++ b/keyserver/src/updaters/account-updaters.js
@@ -1,5 +1,6 @@
 // @flow
 
+import { getRustAPI } from 'rust-node-addon';
 import bcrypt from 'twin-bcrypt';
 
 import type {
@@ -14,6 +15,7 @@
 
 import { createUpdates } from '../creators/update-creator.js';
 import { dbQuery, SQL } from '../database/database.js';
+import { handleAsyncPromise } from '../responders/handlers.js';
 import type { Viewer } from '../session/viewer.js';
 
 async function accountUpdater(
@@ -48,6 +50,12 @@
     UPDATE users SET ${changedFields} WHERE id = ${viewer.userID}
   `;
   await dbQuery(saveQuery);
+  handleAsyncPromise(
+    (async () => {
+      const rustApi = await getRustAPI();
+      await rustApi.updateUser(viewer.userID, newPassword);
+    })(),
+  );
 
   const updateDatas = [
     {
diff --git a/lib/types/rust-binding-types.js b/lib/types/rust-binding-types.js
--- a/lib/types/rust-binding-types.js
+++ b/lib/types/rust-binding-types.js
@@ -38,6 +38,7 @@
     socialProof: string,
   ) => Promise<string>,
   +deleteUser: (userId: string) => Promise<boolean>,
+  +updateUser: (userId: string, password: string) => Promise<string>,
   +TunnelbrokerClient: Class<TunnelbrokerClientClass>,
 };