The Factoring Cryptopocalypse • Hacker News Board

Re: The Factoring Cryptopocalypse

#21

Post by 16s » Sun, Aug 11, 2013, 1:36 PM UTC

kazagistar wrote: post #6

For someone who is somewhat unfamiliar with cryptography, what is the obstacle in creating cryptography that is provably secure: in other words, cryptography that can be absolutely trusted within certain provided parameters.

As others have mentioned. One-time pads are unbreakable:

"While he was at Bell Labs, Shannon proved that the cryptographic one-time pad is unbreakable in his classified research that was later published in October 1949" - http://en.wikipedia.org/wiki/Claude_Shannon

They can also be made to decrypt to any plaintext string

http://16s.us/FreeOTP/nsa/

However, OTP does not scale to more than two or three people, they don't work at all on very large messages as the key has to be as large as the message and they have authentication issues. For two people sending small messages, one-time pads are ideal and if the pads are created, used and destroyed correctly, the encryption is, indeed, unbreakable.

Re: The Factoring Cryptopocalypse

#22

Post by bonzoesc » Sun, Aug 11, 2013, 2:59 PM UTC

kazagistar wrote: post #6

For someone who is somewhat unfamiliar with cryptography, what is the obstacle in creating cryptography that is provably secure: in other words, cryptography that can be absolutely trusted within certain provided parameters.

Usability. One time pads have been around forever, are provably secure, but a pain in the ass.

Modern symmetric ciphers solve the "you need to securely exchange as much key material as you wish to send data" using mathematical formulas to stretch key material. Asymmetric ciphers use mathematical formulas to fix "you need a secure way to exchange keys."

Unfortunately, the math can't be probably secure, only believed secure and proved insecure.

Re: The Factoring Cryptopocalypse

#23

Post by moocowduckquack » Sun, Aug 11, 2013, 3:32 PM UTC

hnha wrote: post #18

ECC means "Elliptic curve cryptography" here, it is not about something with "ECC memory". I've been so confused with all the discussion so far because of this. Dear masters of your domain, if there are acronyms that are not unique, please try not to use them or at least introduce them!

Alternatively, when trying to follow a conversation in a domain specific context, learn the terms.

Re: The Factoring Cryptopocalypse

#24

Post by kazagistar » Sun, Aug 11, 2013, 4:38 PM UTC

bonzoesc wrote: post #22

kazagistar wrote: post #6

For someone who is somewhat unfamiliar with cryptography, what is the obstacle in creating cryptography that is provably secure: in other words, cryptography that can be absolutely trusted within certain provided parameters.

Usability. One time pads have been around forever, are provably secure, but a pain in the ass. Modern symmetric ciphers solve the "you need to securely exchange as much key material as you wish to send data" using mathematical formulas to stretch key material. Asymmetric ciphers use mathematical formulas to fix "you need a secure way to exchange keys." Unfortunately, the math can't be probably secure, only believed s…

Not sure why this is the case though. What makes it inherently impossible to prove something is secure?

Re: The Factoring Cryptopocalypse

#25

Post by Herring » Sun, Aug 11, 2013, 4:57 PM UTC

bonzoesc wrote: post #22

kazagistar wrote: post #6

For someone who is somewhat unfamiliar with cryptography, what is the obstacle in creating cryptography that is provably secure: in other words, cryptography that can be absolutely trusted within certain provided parameters.

Usability. One time pads have been around forever, are provably secure, but a pain in the ass. Modern symmetric ciphers solve the "you need to securely exchange as much key material as you wish to send data" using mathematical formulas to stretch key material. Asymmetric ciphers use mathematical formulas to fix "you need a secure way to exchange keys." Unfortunately, the math can't be probably secure, only believed s…

>Usability. One time pads have been around forever, are provably secure, but a pain in the ass.

With cell phones so widespread, I wondered why someone doesn't write a one time pad app. People could share gigabyte-sized pads via trusted wireless or a cable if they prefer.

http://softthere.com/projects/otp/

Re: The Factoring Cryptopocalypse

#26

Post by damarquis » Sun, Aug 11, 2013, 10:50 PM UTC

Herring wrote: post #25

bonzoesc wrote: post #22

Earlier quoted context omitted.

Usability. One time pads have been around forever, are provably secure, but a pain in the ass. Modern symmetric ciphers solve the "you need to securely exchange as much key material as you wish to send data" using mathematical formulas to stretch key material. Asymmetric ciphers use mathematical formulas to fix "you need a secure way to exchange keys." Unfortunately, the math can't be probably secure, only believed s…

> Usability. One time pads have been around forever, are provably secure, but a pain in the ass. With cell phones so widespread, I wondered why someone doesn't write a one time pad app. People could share gigabyte-sized pads via trusted wireless or a cable if they prefer. http://softthere.com/projects/otp/

The only reason to use one-time pads is an extraordinary level of paranoia. If you are paranoid enough to need a one-time pad then it makes little sense for you as a private citizen to trust that hardware you take into public places hasn't been compromised. Manual creation and transmission of the encrypted message is the only approach that makes sense.

If lots of people adopted one-time pads it might hinder NSA et al but this would be akin to trying to convince people to wear masks whenever they are in public to hinder monitoring with CCTV.