diff --git a/lib/utils/siwe-utils.js b/lib/utils/siwe-utils.js
--- a/lib/utils/siwe-utils.js
+++ b/lib/utils/siwe-utils.js
@@ -52,6 +52,22 @@
   return siweStatementWithPublicKeyRegex.test(candidate);
 }
 
+const publicKeyFromSIWEStatementRegex: RegExp = /[a-zA-Z0-9+/]{43}/;
+function getPublicKeyFromSIWEStatement(statement: string): string {
+  invariant(
+    isValidSIWEStatementWithPublicKey(statement),
+    'candidate must be well formed SIWE statement with public key',
+  );
+  const publicKeyMatchArray = statement.match(publicKeyFromSIWEStatementRegex);
+  invariant(
+    publicKeyMatchArray !== null &&
+      publicKeyMatchArray !== undefined &&
+      publicKeyMatchArray.length === 1,
+    'publicKeyMatchArray should have one and only one element',
+  );
+  return publicKeyMatchArray[0];
+}
+
 export {
   siweStatement,
   isValidSIWENonce,
@@ -60,4 +76,5 @@
   isValidSIWEMessage,
   getSIWEStatementForPublicKey,
   isValidSIWEStatementWithPublicKey,
+  getPublicKeyFromSIWEStatement,
 };
diff --git a/lib/utils/siwe-utils.test.js b/lib/utils/siwe-utils.test.js
--- a/lib/utils/siwe-utils.test.js
+++ b/lib/utils/siwe-utils.test.js
@@ -1,6 +1,7 @@
 // @flow
 
 import {
+  getPublicKeyFromSIWEStatement,
   getSIWEStatementForPublicKey,
   isValidEthereumAddress,
   isValidPrimaryIdentityPublicKey,
@@ -201,4 +202,14 @@
       ),
     ).toBe(true);
   });
+
+  it(`getPublicKeyFromSIWEStatement should pull public key out of valid SIWE statement`, () => {
+    const validSIWEMessageStatement =
+      `Device IdPubKey: rPFzRtV7E6v1b60zjTvghqb2xgnggmn6j4UaYccJYdo ` +
+      `By continuing, I accept the Comm Terms of Service: https://comm.app/terms`;
+
+    expect(getPublicKeyFromSIWEStatement(validSIWEMessageStatement)).toBe(
+      'rPFzRtV7E6v1b60zjTvghqb2xgnggmn6j4UaYccJYdo',
+    );
+  });
 });