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To someone new to crypto, how do companies like WhatsApp implement their end-to-end encryption? Where are keys generated and how are they persisted in a way tha

by seabass 10y ago

To someone new to crypto, how do companies like WhatsApp implement their end-to-end encryption? Where are keys generated and how are they persisted in a way that allows messages to be re-read no matter what device users are running the app from but doesn't allow governments any chance at access to the keys?

shliachtx 10y ago
WhatsApp in particular only allows you to receive messages on one device. WhatsApp web accesses the messages from your phone.
eosrei 10y ago
Whatsapp recently implemented the Signal encryption protocol used in Signal, a FOSS messaging app: https://whispersystems.org/blog/whatsapp-complete/ https://whispersystems.org/blog/whatsapp-complete/ Source is here: https://github.com/WhisperSystems/Signal-Android https://github.com/WhisperSystems/Signal-Android
gjkood 10y ago
If you want to do the heavy lifting in understanding Cryptography, almost all the relevant documentation can be found at the following resource. http://csrc.nist.gov/publications/PubsFIPS.html http://csrc.nist.gov/publications/PubsFIPS.html A lot of the hard (math heavy) stuff used in modern cryptography has been published almost a couple of decades ago and good books are available on Amazon. I usually just buy them used as you get very good deals for books that have been published several years ago. I would recommend Bruce Schneier's 'Applied Cryptography, Protocols, Algorithms and Source Code in C'. I was surprised to see the 20th Anniversary Edition is out now. https://www.amazon.com/Applied-Cryptography-Protocols-Algorithms-Source/dp/1119096723/ref=sr_1_8?ie=UTF8&qid=1466950028&sr=8-8&keywords=cryptography https://www.amazon.com/Applied-Cryptography-Protocols-Algori... The math involved uses a lot of number theory (prime numbers, prime factorization, modulo computations, chinese remainder theorem, elliptic curves, etc) Once you get a basic understanding of the math, you will find out why it is hard to find the keys (if properly generated) through brute force computer attacks.

by seabass 10y ago

shliachtx 10y ago

WhatsApp in particular only allows you to receive messages on one device. WhatsApp web accesses the messages from your phone.

eosrei 10y ago

Whatsapp recently implemented the Signal encryption protocol used in Signal, a FOSS messaging app: https://whispersystems.org/blog/whatsapp-complete/ https://whispersystems.org/blog/whatsapp-complete/ Source is here: https://github.com/WhisperSystems/Signal-Android https://github.com/WhisperSystems/Signal-Android

gjkood 10y ago

If you want to do the heavy lifting in understanding Cryptography, almost all the relevant documentation can be found at the following resource. http://csrc.nist.gov/publications/PubsFIPS.html http://csrc.nist.gov/publications/PubsFIPS.html A lot of the hard (math heavy) stuff used in modern cryptography has been published almost a couple of decades ago and good books are available on Amazon. I usually just buy them used as you get very good deals for books that have been published several years ago. I would recommend Bruce Schneier's 'Applied Cryptography, Protocols, Algorithms and Source Code in C'. I was surprised to see the 20th Anniversary Edition is out now. https://www.amazon.com/Applied-Cryptography-Protocols-Algorithms-Source/dp/1119096723/ref=sr_1_8?ie=UTF8&qid=1466950028&sr=8-8&keywords=cryptography https://www.amazon.com/Applied-Cryptography-Protocols-Algori... The math involved uses a lot of number theory (prime numbers, prime factorization, modulo computations, chinese remainder theorem, elliptic curves, etc) Once you get a basic understanding of the math, you will find out why it is hard to find the keys (if properly generated) through brute force computer attacks.