diff --git a/themes/default/public/js/lufi-down.js b/themes/default/public/js/lufi-down.js
index 9ba9999..386bbf7 100644
--- a/themes/default/public/js/lufi-down.js
+++ b/themes/default/public/js/lufi-down.js
@@ -35,18 +35,6 @@ function pageKey() {
     return key;
 }
 
-function base64ToArrayBuffer(base64) {
-    base64 = base64 instanceof ArrayBuffer ? new TextDecoder().decode(base64) : base64; // Is it using Lufi API?
-
-    var binary_string = window.atob(base64);
-    var len = binary_string.length;
-    var bytes = new Uint8Array(len);
-    for (var i = 0; i < len; i++) {
-        bytes[i] = binary_string.charCodeAt(i);
-    }
-    return bytes.buffer;
-}
-
 // Something's wring
 function addAlert(msg) {
     $('#please-wait').remove();
@@ -124,9 +112,7 @@ function spawnWebsocket(pa) {
             $('#pbt').html(`${percent}%`);
             try {
                 lufiApi.lufiCrypto.decrypt(window.key, slice).then((decrypted) => {
-                    var b64 = decrypted;
-
-                    window.a[data.part] = base64ToArrayBuffer(b64);
+                     window.a[data.part] = decrypted;
 
                     if (data.part + 1 === data.total) {
                         var blob = new Blob(a, { type: data.type });
diff --git a/themes/default/public/js/lufi-up.js b/themes/default/public/js/lufi-up.js
index 9d967fc..69d5c5f 100644
--- a/themes/default/public/js/lufi-up.js
+++ b/themes/default/public/js/lufi-up.js
@@ -357,23 +357,12 @@ function sliceAndUpload(randomKey, i, parts, j, delay, del_at_first_view, short,
     } else {
         var file = window.fileList[i];
         var slice = file.slice(j * window.sliceLength, (j + 1) * window.sliceLength, file.type);
-        var fr = new FileReader();
 
-        fr.onloadend = function() {
-            var sl        = $(`#parts-${window.fc}`);
-
-            // Get the binary result, different result in IE browsers (see default.html.ep line 27:48)
-            if (isIE == true) {
-                var bin = fr.content;
-            } else {
-                var bin = fr.result;
-            }
-
-            // Transform it in base64
-            var b = window.btoa(bin);
+        slice.arrayBuffer().then((sliceArrayBuffer) => {
+            var sl = $(`#parts-${window.fc}`);
 
             // Encrypt it
-            lufiApi.lufiCrypto.encrypt(randomKey, new TextEncoder().encode(b).buffer).then((encryptedFile) => {
+            lufiApi.lufiCrypto.encrypt(randomKey, sliceArrayBuffer).then((encryptedFile) => {
                 let encrypted = encryptedFile;
 
                 // Prepare json
@@ -431,12 +420,8 @@ function sliceAndUpload(randomKey, i, parts, j, delay, del_at_first_view, short,
 
                     window.ws.send(data);
                 }
-            }).catch((e) => {
-                console.error(e);
-            })
-        }
-
-        fr.readAsBinaryString(slice);
+            }).catch((e) => console.error(e))
+        }).catch((e) => console.error(e))
     }
 }