A few fixes/organized to the courses playlist

README.md

@@ -1651,7 +1651,7 @@ Sit back and enjoy. "netflix and skill" :P
 
 - [ ] [Computer Science 70, 001 - Spring 2015 - Discrete Mathematics and Probability Theory](https://www.youtube.com/playlist?list=PL-XXv-cvA_iD8wQm8U0gG_Z1uHjImKXFy)
 
-- [ ] [Discrete Mathematics (19 videos)](https://www.youtube.com/playlist?list=PL3o9D4Dl2FJ9q0_gtFXPh_H4POI5dK0yG)
+- [ ] [Discrete Mathematics by Shai Simonson (19 videos)](https://www.youtube.com/playlist?list=PL3o9D4Dl2FJ9q0_gtFXPh_H4POI5dK0yG)
 
 - [ ] CSE373 - Analysis of Algorithms (25 videos)
     - [Skiena lectures from Algorithm Design Manual](https://www.youtube.com/watch?v=ZFjhkohHdAA&list=PLOtl7M3yp-DV69F32zdK7YJcNXpTunF2b&index=1)
@@ -1686,13 +1686,14 @@ Sit back and enjoy. "netflix and skill" :P
 
 - [ ] [MIT 6.854: Advanced Algorithms, Spring 2016 (24 videos)](https://www.youtube.com/playlist?list=PL6ogFv-ieghdoGKGg2Bik3Gl1glBTEu8c)
 
-- [ ] [MIT 6.858 Computer Systems Security, Fall 2014](https://www.youtube.com/watch?v=GqmQg-cszw4&index=1&list=PLUl4u3cNGP62K2DjQLRxDNRi0z2IRWnNh)
+- [ ] [HARVARD COMPSCI 224: Advanced Algorithms (25 videos)](https://www.youtube.com/playlist?list=PL2SOU6wwxB0uP4rJgf5ayhHWgw7akUWSf)
 
-- [ ] Stanford: Programming Paradigms (17 videos)
-    - [Course on C and C++](https://www.youtube.com/watch?v=jTSvthW34GU&list=PLC0B8B318B7394B6F&nohtml5=False)
+- [ ] [MIT 6.858 Computer Systems Security, Fall 2014](https://www.youtube.com/watch?v=GqmQg-cszw4&index=1&list=PLUl4u3cNGP62K2DjQLRxDNRi0z2IRWnNh)
 
-- [ ] [Introduction to Cryptography](https://www.youtube.com/watch?v=2aHkqB2-46k&feature=youtu.be)
-    - [more in series (not in order)](https://www.youtube.com/channel/UC1usFRN4LCMcfIV7UjHNuQg)
+- [ ] [Stanford: Programming Paradigms (17 videos)](https://www.youtube.com/view_play_list?p=9D558D49CA734A02)
+
+- [ ] [Introduction to Cryptography by Christof Paar](https://www.youtube.com/playlist?list=PL6N5qY2nvvJE8X75VkXglSrVhLv1tVcfy)
+    - [Course Website along with Slides and Problem Sets](http://www.crypto-textbook.com/)
 
 - [ ] [Mining Massive Datasets - Stanford University (94 videos)](https://www.youtube.com/playlist?list=PLLssT5z_DsK9JDLcT8T62VtzwyW9LNepV)