diff --git a/README.md b/README.md
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@@ -77,7 +77,7 @@ It will be extended gradually as I find something of "must-have" value. Pull req
 * [ChaCha20-Poly1305 Cipher Suites for Transport Layer Security (TLS)](https://tools.ietf.org/html/draft-ietf-tls-chacha20-poly1305-04) - IETF Draft of ciphersuite family, by Adam Langley et al.
 * [AES submission document on Rijndael](https://csrc.nist.gov/csrc/media/projects/cryptographic-standards-and-guidelines/documents/aes-development/rijndael-ammended.pdf#page=1) - Original Rijndael proposal by Joan Daemen and Vincent Rijmen.
 * [Ongoing Research Areas in Symmetric Cryptography](https://web.archive.org/web/20220209130448/https://www.ecrypt.eu.org/ecrypt1/documents/D.STVL.3-2.5.pdf) - Overview of ongoing research in secret key crypto and hashes by ECRYPT Network of Excellence in Cryptology.
-* [The Galois/Counter Mode of Operation (GCM)](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.694.695&rep=rep1&type=pdf) - Original paper introducing GCM, by by David A. McGrew and John Viega.
+* [The Galois/Counter Mode of Operation (GCM)](https://web.archive.org/web/20221007191258/https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.694.695&rep=rep1&type=pdf) - Original paper introducing GCM, by by David A. McGrew and John Viega.
 * [The Security and Performance of the Galois/Counter Mode (GCM) of Operation](https://eprint.iacr.org/2004/193.pdf) - Design, analysis and security of GCM, and, more specifically, AES GCM mode, by David A. McGrew and John Viega.
 * [GCM Security Bounds Reconsidered](https://www.iacr.org/archive/fse2015/85400168/85400168.pdf) - An analysis and algorithm for nonce generation for AES GCM with higher counter-collision probability, by Yuichi Niwa, Keisuke Ohashi, Kazuhiko Minematsu, Tetsu Iwata.
 * [Proxy-Mediated Searchable Encryption in SQL Databases Using Blind Indexes](https://eprint.iacr.org/2019/806.pdf) - An overview of existing searchable encryption schemes, and analysis of scheme built on AES-GCM, blind index and bloom filter by Eugene Pilyankevich, Dmytro Kornieiev, Artem Storozhuk.
@@ -137,11 +137,11 @@ It will be extended gradually as I find something of "must-have" value. Pull req
 * [How to construct zero-knowledge proof systems for NP](http://www.wisdom.weizmann.ac.il/~oded/gmw1.html) - Classic paper by Goldreich,  Micali and Wigderson.
 * [Proofs that yield nothing but their validity and a Methodology of Cryptographic protocol design](http://www.math.ias.edu/~avi/PUBLICATIONS/MYPAPERS/GMW86/GMW86.pdf) - By Goldreich,  Micali and Wigderson, a relative to the above. 
 * [A Survey of Noninteractive Zero Knowledge Proof System and Its Applications](https://www.hindawi.com/journals/tswj/2014/560484/).
-* [How to Prove a Theorem So No One Else Can Claim It](https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.469.9048&rep=rep1&type=pdf) - By Manuel Blum.
+* [How to Prove a Theorem So No One Else Can Claim It](https://web.archive.org/web/20211122040931/https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.469.9048&rep=rep1&type=pdf) - By Manuel Blum.
 * [Information Theoretic Reductions among Disclosure Problems](http://crypto.cs.mcgill.ca/~crepeau/BCR86.pdf) - Brassau et al.
 * [Knowledge complexity of interactive proof systems](https://github.com/manjunath5496/Shafi-Goldwasser-Publications/blob/master/1989-siamjc.pdf) - By GoldWasser, Micali and Rackoff. Defining computational complexity of "knowledge" within zero knowledge proofs. 
 * [A Survey of Zero-Knowledge Proofs with Applications to Cryptography](http://www.austinmohr.com/work/files/zkp.pdf) - Great intro on original ZKP protocols.
-* [Zero Knowledge Protocols and Small Systems](https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.186.4901&rep=rep1&type=pdf) - A good intro into Zero knowledge protocols.
+* [Zero Knowledge Protocols and Small Systems](https://web.archive.org/web/20220211100630/https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.26.585&rep=rep1&type=pdf) - A good intro into Zero knowledge protocols.
 * [Multi-Theorem Preprocessing NIZKs from Lattices](https://link.springer.com/chapter/10.1007%2F978-3-319-96881-0_25) - Construction of non-interactive zero-knowledge (NIZK) proofs using lattice-based preprocessing models, by Sam Kim and David J. Wu.
 
 #### Key Management