Crypto Apparatuur & Geschiedenis

Crypto Museum (Paul Reuvers & Marc Simons)
Enigma Museum (Tom Perera)
Bob Lord's Online Crypto Museum (Bob Lord)
Dr Enigma (Mark Baldwin)
Chiffriermachine (Patrick Heyes)

Crypto Machines (Jerry Proc)
Cipher History (Ralph Simpson)
Ultrasecret (Richard Brisson)
Fialka Pages (Tom Perera)
Crypto Room (Mark Blair)

Crypto Cellar (Frode Weierud)
US Navy Crypto Equipment (Nick England)
Breaking German Navy Ciphers (Michael Hörenberg)
Bletchley Park Museum
Tony Sale's Codes & Ciphers

Intelligenia.org (David Hamer) *
Enigma and the Bombe
Erik Vestergaards Enigma page
Enigma on the German U-Boats

Cryptografie & Intel

NSA Center for Cryptologic History
NSA Declassified Documents
NSA Cryptologic Museum

CrypTool - Cryptography & Cryptanalysis
Cryptography for Everybody on Youtube
CryptoBooks.org
MysteryTwister C3

Handbook of Applied Cryptography
Claude Shannon's Communications Theory

John Savard's Crypto Pages
Der SAS- und Chiffrierdienst
Nicholas Gessler's Collection
Simon Singh's Black Chamber
Brooke Clarkes Crypto and EW pages

International Conference on Cryptologic History
American Cryptogram Association
Practical Aspects of Modern Cryptography
Ron Rivest' MIT pages
CryptoCollectors at groups.io

ENIGMA2000 Numbers Stations Monitoring
RN Communications Branche Museum
Loistava Information Security
Didier Muller's Ars Cryptographica
Crypto Law Survey
Naked Security - Crypto

SIGINT Chatter
Crypto Cellar Tales (Frode Weierud)
Cipherbrain (Klaus Schmeh)
SIGINT Historian (Tony Comer)
The Sunday Download (Gary Ruddell)

Electrospaces
Intelnews
Unredacted
FAS Secrecy News
Lux Ex Umbra

Christos Mil & Intel Corner
Nuclear Secrecy
Atomic Annihilation
Atomic Skies
COMSEC LLC - Spy vs Spy

The SWLing Post
Cyberwar (Matthijs R. Koot)
Underground Tradecraft
SpyBlog
Cryptome

The Intercept
Agentura
Loistava Blog

Simulaties & Software

Enigma simulations by CSG
Daniel Palloks Enigmas in Javascript
Enigma Flash Simulation
Arduino Enigma Simulator
Enigma M3 Emulator on 101 Computing

Public (E) Enigma van aperopia
Virtual Colossus by Martin Gillow
Virtual Enigma by Martin Gillow
Turing & US Navy Bombe, Magnus & Hallenberg

J-F Bouchaudy's' Crypto & Simulators
J-F Bouchaudy's Bombe Simulator (zip)
Dinah's C# Enigma Simulator

Diverse

The National Security Archive
Governmentattic.org
The Nuclear Vault
Federation of American Scientist
Foundation for German communication

RN Communications Branche Museum
Espionage History Archive
Naked Security
War on the Rocks

Podcasts

Malicious Life
Darknet Diaries
Cold War Conversations
The Cold War Vault
History of the Cold War

SpyCast
Spy Museum on C-SPAN
True Spies (Spyscape)
Spycraft 101
The Live Drop

Secrets & Spies
Naked Security