4 ms·

For anyone interested, I think these are the PDFs for the first and second books: Part 1: https://www.nsa.gov/Portals/70/documents/news-features/declassified-d

For anyone interested, I think these are the PDFs for the first and second books: Part 1: https://www.nsa.gov/Portals/70/documents/news-features/declassified-documents/friedman-documents/publications/FOLDER_242/41748189078749.pdf https://www.nsa.gov/Portals/70/documents/news-features/decla... Part 2: https://www.nsa.gov/Portals/70/documents/news-features/declassified-documents/friedman-documents/publications/FOLDER_257/41751589079090.pdf https://www.nsa.gov/Portals/70/documents/news-features/decla...

comboy 5y ago
How does content of this compares to e.g. newer (still 30 year old) book like Applied Cryptography by Schneier? I understand these PDFs are even more "applied" but in terms of concepts behind them?
- elahieh 5y ago
  This book, like the MILCRYP series, is focussed on cryptanalysis of "classical" (pre-computer) ciphers. The "Principles of Cryptodiagnosis" chapter (which I think is the most interesting "reveal") is an update of the author's 1970 monograph "Ars Conjectandi". Around 1976/1977 when the book came out, the stronger "modern" cryptography was becoming public - DES, public key crypto, Diffie-Hellman key exchange, the paper "New Directions in Cryptography" etc. The Schneier book is all about those - e.g. DES, RSA, GOST etc and applying known systems. It's not about cryptanalysis of pre-computer "classical systems" - at the start he says "This is not a book about classical cryptography". There's a brief note mentioning that "double transposition" is a very strong classical system, and that's about it.
  - schoen 5y ago
    Also, Schneier is trying to teach people how to implement cryptosystems, not how to break them or how to design them (which you allude to by saying "applying known systems"). One difference between classical and modern cryptography is that classical cryptography usually works at the letter or character level, while modern cryptography usually treats plaintexts and ciphertexts as uninterpreted sequences of bits and uses bit-level operations. Sometimes these two perspectives have equivalences or similarities, but mostly not if you're looking at stuff like block cipher S-boxes or block cipher modes of operation or Merkle-Damgård hash functions or whatever.
  - comboy 5y ago
    Thanks!
gshubert17 5y ago
The first link, for Part 1, is great. Part 2 seems to have been published in 3 sections. The second link is to the second section of Part 2, with a REF ID of A64556. This contains parts 10 through 14 and 3 appendices. If anyone is interested, a link to the first section, which contains parts 1-9, REF ID A64563, is at: https://archive.org/details/41752229079148 https://archive.org/details/41752229079148 or https://www.nsa.gov/Portals/70/documents/news-features/declassified-documents/friedman-documents/publications/FOLDER_253/41752229079148.pdf https://www.nsa.gov/Portals/70/documents/news-features/decla... And the third section, with appendices 4-9, REF ID A64556 is at: https://archive.org/details/41751819079101 https://archive.org/details/41751819079101 or https://www.nsa.gov/Portals/70/documents/news-features/declassified-documents/friedman-documents/publications/FOLDER_257/41751819079101.pdf https://www.nsa.gov/Portals/70/documents/news-features/decla... The Internet Archive has a large collection of documents from American cryptographer William F. Friedman, which was easier to search than the NSA's site.

comboy 5y ago

How does content of this compares to e.g. newer (still 30 year old) book like Applied Cryptography by Schneier? I understand these PDFs are even more "applied" but in terms of concepts behind them?

elahieh 5y ago
This book, like the MILCRYP series, is focussed on cryptanalysis of "classical" (pre-computer) ciphers. The "Principles of Cryptodiagnosis" chapter (which I think is the most interesting "reveal") is an update of the author's 1970 monograph "Ars Conjectandi". Around 1976/1977 when the book came out, the stronger "modern" cryptography was becoming public - DES, public key crypto, Diffie-Hellman key exchange, the paper "New Directions in Cryptography" etc. The Schneier book is all about those - e.g. DES, RSA, GOST etc and applying known systems. It's not about cryptanalysis of pre-computer "classical systems" - at the start he says "This is not a book about classical cryptography". There's a brief note mentioning that "double transposition" is a very strong classical system, and that's about it.
- schoen 5y ago
  Also, Schneier is trying to teach people how to implement cryptosystems, not how to break them or how to design them (which you allude to by saying "applying known systems"). One difference between classical and modern cryptography is that classical cryptography usually works at the letter or character level, while modern cryptography usually treats plaintexts and ciphertexts as uninterpreted sequences of bits and uses bit-level operations. Sometimes these two perspectives have equivalences or similarities, but mostly not if you're looking at stuff like block cipher S-boxes or block cipher modes of operation or Merkle-Damgård hash functions or whatever.
- comboy 5y ago
  Thanks!

gshubert17 5y ago

The first link, for Part 1, is great. Part 2 seems to have been published in 3 sections. The second link is to the second section of Part 2, with a REF ID of A64556. This contains parts 10 through 14 and 3 appendices. If anyone is interested, a link to the first section, which contains parts 1-9, REF ID A64563, is at: https://archive.org/details/41752229079148 https://archive.org/details/41752229079148 or https://www.nsa.gov/Portals/70/documents/news-features/declassified-documents/friedman-documents/publications/FOLDER_253/41752229079148.pdf https://www.nsa.gov/Portals/70/documents/news-features/decla... And the third section, with appendices 4-9, REF ID A64556 is at: https://archive.org/details/41751819079101 https://archive.org/details/41751819079101 or https://www.nsa.gov/Portals/70/documents/news-features/declassified-documents/friedman-documents/publications/FOLDER_257/41751819079101.pdf https://www.nsa.gov/Portals/70/documents/news-features/decla... The Internet Archive has a large collection of documents from American cryptographer William F. Friedman, which was easier to search than the NSA's site.