diff --git a/src/user/reporting/ReportMenu.tsx b/src/user/reporting/ReportMenu.tsx
index d8de026e..c9fdd45a 100644
--- a/src/user/reporting/ReportMenu.tsx
+++ b/src/user/reporting/ReportMenu.tsx
@@ -18,7 +18,6 @@ import {
 import KeyboardArrowDownIcon from "@mui/icons-material/KeyboardArrowDown";
 import KeyboardArrowUpIcon from "@mui/icons-material/KeyboardArrowUp";
 import DownloadIcon from "@mui/icons-material/Download";
-import { uInt8Array } from "util/uInt8Array";
 
 interface ReportMenuProps {
   hasVerifiedConversions: boolean;
@@ -32,8 +31,6 @@ export const ReportMenu = ({
   const [isError, setIsError] = useState(false);
   const set = (s: string) =>
     document.getElementById("private-key")?.setAttribute("value", s);
-  const get = () =>
-    document.getElementById("private-key")?.getAttribute("value");
   const { download, loading, error } = useDownloadCSV({
     onComplete() {
       setAnchorEl(null);
@@ -134,7 +131,7 @@ export const ReportMenu = ({
           <Button
             variant="contained"
             onClick={() => {
-              download(campaignId, true, uInt8Array(get()));
+              download(campaignId, true);
             }}
             disabled={loading}
           >
diff --git a/src/user/reporting/csv.library.tsx b/src/user/reporting/csv.library.tsx
index 7963bd28..d6b55bec 100644
--- a/src/user/reporting/csv.library.tsx
+++ b/src/user/reporting/csv.library.tsx
@@ -2,7 +2,7 @@ import { useCallback, useState } from "react";
 import { buildAdServerEndpoint } from "util/environment";
 import Papa from "papaparse";
 import tweetnacl from "tweetnacl";
-import { uInt8Array } from "util/uInt8Array";
+
 interface DownloadProps {
   onComplete?: () => void;
   onError?: () => void;
@@ -12,75 +12,74 @@ export function useDownloadCSV(props: DownloadProps = {}) {
   const [loading, setLoading] = useState(false);
   const [error, setError] = useState<string>();
 
-  const download = useCallback(
-    (campaignId: string, isVac: boolean, privateKey?: Uint8Array) => {
-      setLoading(true);
-      setError(undefined);
+  const download = useCallback((campaignId: string, isVac: boolean) => {
+    setLoading(true);
+    setError(undefined);
 
-      const baseUrl = `/report/campaign/csv/${campaignId}`;
-      fetch(buildAdServerEndpoint(isVac ? `${baseUrl}/vac` : baseUrl), {
-        method: "GET",
-        mode: "cors",
-        credentials: "include",
-        headers: {
-          "Content-Type": "text/csv",
-        },
-      })
-        .then((res) => {
-          if (res.status !== 200) {
-            const err = "Unable to download CSV";
-            setError(err);
-            throw new Error(err);
-          }
+    const baseUrl = `/report/campaign/csv/${campaignId}`;
+    fetch(buildAdServerEndpoint(isVac ? `${baseUrl}/vac` : baseUrl), {
+      method: "GET",
+      mode: "cors",
+      credentials: "include",
+      headers: {
+        "Content-Type": "text/csv",
+      },
+    })
+      .then((res) => {
+        if (res.status !== 200) {
+          const err = "Unable to download CSV";
+          setError(err);
+          throw new Error(err);
+        }
 
-          return res.blob();
-        })
-        .then((blob) => {
-          const file = new Blob([blob], {
-            type: "text/csv",
-            endings: "transparent",
-          });
+        return res.blob();
+      })
+      .then((blob) => {
+        const file = new Blob([blob], {
+          type: "text/csv",
+          endings: "transparent",
+        });
 
-          if (isVac) {
-            return transformConversionEnvelope(file, privateKey);
-          }
+        if (isVac) {
+          return transformConversionEnvelope(file);
+        }
 
-          return Promise.resolve(file);
-        })
-        .then((file) => {
-          const fileURL = URL.createObjectURL(file);
-          const link = document.createElement("a");
-          link.href = fileURL;
-          link.setAttribute("download", `${campaignId}.csv`);
-          document.body.appendChild(link);
-          link.click();
-          if (props.onComplete) props.onComplete();
-        })
-        .catch((e) => {
-          setError(e.message);
-        })
-        .finally(() => {
-          setLoading(false);
-          privateKey?.fill(0);
-        });
-    },
-    [],
-  );
+        return Promise.resolve(file);
+      })
+      .then((file) => {
+        const fileURL = URL.createObjectURL(file);
+        const link = document.createElement("a");
+        link.href = fileURL;
+        link.setAttribute("download", `${campaignId}.csv`);
+        document.body.appendChild(link);
+        link.click();
+        if (props.onComplete) {
+          props.onComplete();
+        }
+      })
+      .catch((e) => {
+        setError(e.message);
+      })
+      .finally(() => {
+        setLoading(false);
+      });
+  }, []);
 
   return { download, loading, error };
 }
 
 type Envelope = { ciphertext: string; epk: string; nonce: string };
-async function transformConversionEnvelope(
-  blob: Blob,
-  privateKey?: Uint8Array,
-): Promise<Blob> {
-  if (!privateKey) {
+async function transformConversionEnvelope(blob: Blob): Promise<Blob> {
+  const ui8a = (s?: string | null) =>
+    s ? Uint8Array.from(atob(s), (c) => c.charCodeAt(0)) : new Uint8Array();
+  const privateKey = ui8a(
+    document.getElementById("private-key")?.getAttribute("value"),
+  );
+  if (privateKey.byteLength === 0) {
     return Promise.resolve(blob);
   }
 
   const td = new TextDecoder();
-
   return await new Promise((resolve, reject) => {
     const fileReader = new FileReader();
     fileReader.onload = () => {
@@ -98,9 +97,9 @@ async function transformConversionEnvelope(
             if (field.includes("Conversion")) {
               const { ciphertext, nonce, epk }: Envelope = JSON.parse(value);
               const res = tweetnacl.box.open(
-                uInt8Array(ciphertext),
-                uInt8Array(nonce),
-                uInt8Array(epk),
+                ui8a(ciphertext),
+                ui8a(nonce),
+                ui8a(epk),
                 privateKey,
               );
               return res
@@ -114,6 +113,7 @@ async function transformConversionEnvelope(
             const newCSV = Papa.unparse(results.data, {
               skipEmptyLines: "greedy",
             });
+            privateKey.fill(0);
             resolve(new Blob([newCSV]));
           },
           error(error: Error) {
diff --git a/src/util/uInt8Array.ts b/src/util/uInt8Array.ts
deleted file mode 100644
index eeee793c..00000000
--- a/src/util/uInt8Array.ts
+++ /dev/null
@@ -1,4 +0,0 @@
-export const uInt8Array = (s?: string | null) =>
-  s
-    ? Uint8Array.from(atob(s), (c) => c.charCodeAt(0))
-    : new Uint8Array().fill(0);