diff --git a/cryptography/README.md b/cryptography/README.md
index ae44a98..c05751a 100644
--- a/cryptography/README.md
+++ b/cryptography/README.md
@@ -1 +1,2 @@
 * [A Method for Obtaining Digital Signatures and Public-Key Cryptosystems](http://people.csail.mit.edu/rivest/Rsapaper.pdf)
+* [Twenty Years of Attacks on the RSA Cryptosystem](https://crypto.stanford.edu/~dabo/papers/RSA-survey.pdf)