Update README.md

Author: gap-editor

README.md

@@ -73,7 +73,7 @@ Unfortunately, this isn't a silver bullet.
 Often, Javascript itself is working against us by bypassing these counter-measures.
 
 Problems in [`Buffer (UInt8Array)`](https://github.com/feross/buffer), for example, can trivially result in **catastrophic fund loss** without any warning.
-It can do this through undermining your random number generation, accidentally producing a [duplicate `k` value](https://www.nilsschneider.net/2013/01/28/recovering-bitcoin-private-keys.html), sending Bitcoin to a malformed output script, or any of a million different ways.
+It can do this through undermining your random number generation, accidentally producing a [duplicate `k` value](https://web.archive.org/web/20160308014317/http://www.nilsschneider.net/2013/01/28/recovering-bitcoin-private-keys.html), sending Bitcoin to a malformed output script, or any of a million different ways.
 Running tests in your target environment is important and a recommended step to verify continuously.
 
 Finally, **adhere to best practice**.