Books and academic papers

An Introduction to Mathematical Cryptography

Jeffrey Hoffstein, Jill Pipher and Joseph H. Silverman

This book focuses on public key cryptography and no prerequisites in higher mathematics are needed, which makes it a great first book in cryptography.

Cryptography: Theory and Practice (Third Edition)

Douglas R. Stinson

A mathematically intensive examination of cryptography that makes it difficult for the reader with little or no mathematics background.

Cryptography Engineering: Design Principles and Practical Applications

Niels Ferguson, Bruce Schneier and Tadayoshi Kohno

Focuses on the implementation of cryptography in practice systems and the choices developers are faced with.

The Codebreakers

David Kahn

The history of cryptography and its impact on the history from the very beginning to today.

Handbook of Applied Cryptography

Alfred J. Menezes, Paul C. van Oorschot and Scott A. Vanstone

A great free online book that covers all the important areas of cryptography.

A Graduate Course in Applied Cryptography

Dan Boneh and Victor Shoup

Another great free online book from a graduate course in applied cryptography from Stanford University.

New Directions in Cryptography

Whitfield Diffie and Martin E. Hellman

The famous paper by Whitfield Diffie and Martin Hellman, which was the beginning of public key cryptography as we know it today.

Articles

schneier.com
The homepage of IT security and cryptography expert Bruce Schneier, where he is blogging about security.
grahamcluley.com
The homepage of IT security expert Graham Cluley where he is blogging about security.
schneier.com
Bruce Schneier on why encryption is important for yourself and other.
iacr.org
Website of the International Association for Cryptologic Research where news and papers from the academic world are published.
wired.com
Article about the tools Laura Poitras used to communicate securely with Edward Snowden and keep her work on the documentary Citizenfour safe.
firstlook.org/theintercept
Interesting article about how journalists and their sources use secure communication.
spiegel.de
Status of NSA's work on breaking encryption (the article is in english).
wired.com
How one hacker in 30 min hacked into a persons iCloud, Gmail and Twitter account by exploiting companies different security police.
grahamcluley.com
How to hack into an email account just by knowing the victim's mobile phone number.
wired.com
How hackers remotely killed a Jeep Cherokee on the highway.
wired.com
How to disable a sniper rifle or change its target.
fusion.net
A video illustrating how powerful social engineering is.
troyhunt.com
Security expert Troy Hunt's list of security links.
varonis.com
Top 10 security people to follow on twitter.
ted.com
Glenn Greenwald at TED in 2014 on why privacy matters.
symantec.com
Symantecs annual threat report, which provides an overview and analysis of the year in global threat activity.

Guides

ssd.eff.org
Tips, tools and how-tos for safer online communications.
privacytools.io
Provides knowledge and tools to protect your privacy against global mass surveillance.
freedom.press
A guide by Micah Lee on how to protect your privacy. Micah Lee helped among other things Glenn Greenwald to setup secure communication with Edward Snowden back in 2013.
firstlook.org
A guide to create a safe password with a method called "diceware".
firstlook.org/theintercept
Micah Lee on how to chat securely and anonymously on Windows, MAC and Android.
theguardian.com
A guide to stay secure by Bruce Schneier.
freedom.press
Why Flash is dangerous and how to deal with it in the browser.
medium.com
Guide to tightening you security with VPN, encryption, safe passwords etc.
lifehacker.com
Why you should use a VPN provider and how to choose the best one.
comparitech.com
A review of the best VPN providers rated on privacy and security.
khanacademy.org
Khan Academy on cryptography.
coursera.org
Online cryptography course at Stanford University.
keylength.com
Recommended key size of various cryptosystems such as RSA, ElGamal, AES and hash functions.

Tools

Tor Browser
A browser to surf the web anonymously.
HTTPS Everywhere
Making your browsing more secure by encrypting your communication. Extension for Firefox, Chrome, Opera and Android.
Ghostery
See which websites that tracks you while you are surfing the web and makes it possible to block them. Extension for Firefox, Chrome, Safari and Opera.
Disconnect
Another service that show and block tracking website. Extension for Firefox, Chrome, Safari and Opera.
uBlock
uBlock is a content blocker for your browser, that makes your web experience faster by e.g. blocking ads. Extension for Firefox, Chrome and Safari.
1Password
Software to manage your passwords for Mac, Windows, iOS and Android.
LastPass
Alternative free password manager for Mac, Windows, Linux, iOS, Android, Windows Phone and Black Berry.
F-Secure Freedome
VPN for Mac, Windows, iOS, Android and Kindle Fire inclusive extra security features such as add blocking.
GPGTools
PGP software for Mac, which is used to encrypt your emails.
Gpg4win
A Windows version of the PGP software.
GnuPG
And finally a Linux version of the PGP software.
pgp.mit.edu
A database of public PGP keys at MIT.
Cryptocat
Secure browser-based chat program for Chrome, Firefox, Safari, Opera, iOS and OS X.
Bleep
Chat privately in iOS, Android, Mac and Windows where received messages self destroy after a short amount of time just like pictures in Snapchat.
Adium
Chat client for MAC that encrypt your communication with OTR (Off The Record).
Pidgin
A Windows version of the chat client where the OTR extension can be downloaded from the same webpage.
Tor Messenger
OTR (Off The Record) chat client for Windows, Mac and Linux developed by the Tor Project.
Open Whisper Systems
Open Whisper Systems have created an app for iOS and Android called Signal that lets you communicate securely (even Edward Snowden use Signal).
Ricochet
An anonymously and secure chat program, which use the Tor network.
ProtonMail
A secure mail services with end-to-end encryption.
OnionShare
Securely and anonymously share a file of any size.
miniLock
Extension for Chrome that can be used to send encrypted files to another miniLock user.
SecureDrop
A service that let other people anonymously send you documents and messages.
Boxcrypter
Encrypt your files and folders in Dropbox.
Tails
Live operation system that protect your privacy and keep you anonymous.
haveibeenpwned.com
Check if you have an account that has been compromised in a data breach.