3 files changed, 18 insertions, 0 deletions

diff --git a/src/css/app.css b/src/css/app.css
index 576b7d7..c2a0294 100644
--- a/src/css/app.css
+++ b/src/css/app.css
@@ -31,6 +31,10 @@ body {
 .phrase {
     word-break: keep-all;
 }
+.phraseSplitWarn {
+        text-align: right;
+        color: red;
+}
 .generate-container .strength {
     /* override mobile width from bootstrap */
     width: auto!important;
diff --git a/src/index.html b/src/index.html
index 8862904..bfb2bc1 100644
--- a/src/index.html
+++ b/src/index.html
@@ -177,6 +177,7 @@
                             <div class="col-sm-10">
                                 <textarea id="phraseSplit" class="phraseSplit private-data form-control" title="Only 2 of 3 cards needed to recover."></textarea>
                             </div>
+                                                        <div id="phraseSplitWarn" class="phraseSplitWarn"></div>
                         </div>
                         <div class="form-group">
                             <label for="passphrase" class="col-sm-2 control-label">BIP39 Passphrase (optional)</label>
diff --git a/src/js/index.js b/src/js/index.js
index 035a2b3..9d5f8ee 100644
--- a/src/js/index.js
+++ b/src/js/index.js
@@ -45,6 +45,7 @@
     DOM.entropyFilterWarning = DOM.entropyContainer.find(".filter-warning");
     DOM.phrase = $(".phrase");
         DOM.splitPhrase = $(".phraseSplit");
+        DOM.phraseSplitWarn = $(".phraseSplitWarn");
     DOM.passphrase = $(".passphrase");
     DOM.generateContainer = $(".generate-container");
     DOM.generate = $(".generate");
@@ -1448,6 +1449,18 @@
                         cards[i]='Card '+(i+1)+': '+wordArrayToPhrase(cards[i]);                                                                //combine words on card back to string
                 }
                 DOM.splitPhrase.val(cards.join("\r\n"));                                                                //make words visible
+                var triesPerSecond=10000000000;                                                                                 //assumed number of tries per second
+                var hackTime=Math.pow(2,wordCount*10/3)/triesPerSecond;                                 //get number of bits of unknown data per card
+                if (hackTime<1) {
+                        hackTime="<1 second";
+                } else if (hackTime<86400) {
+                        hackTime=Math.floor(hackTime)+" seconds";
+                } else if(hackTime<31557600) {
+                        hackTime=Math.floor(hackTime/86400)+" days";
+                } else {
+                        hackTime=Math.floor(hackTime/31557600)+" years";
+                }
+                DOM.phraseSplitWarn.html("Time to hack with only one card: "+hackTime);
         }
 
     function isUsingOwnEntropy() {