In this case it does because it makes PIN blocks encrypted using the same working key be completely different. This prevents someone from performing a chosen plaintext attack by setting their own PIN to be 0000 or 1234 and comparing the captured PIN block to others. More of a limited rainbow table I guess.
Take a look at DUKPT, short for Derived Unique Key Per Transaction, to better understand how a PIN pad can be loaded with a set of keys that the merchant does not know. Similarly many PIN pads support remote key loading where asymmetric encryption is used to send a random 'working' 3DES key to the terminal. That key will be periodically replaced with a new one. Again the merchant has no idea what key is being used by the terminal at any given time.
PIN blocks are encrypted using PIN block
format 0. In this format a portion of the account number is XORed with the PIN block prior to encryption. The result is that for two different accounts with the same PIN, even if they are encrypted with the same key, the resulting encrypted PIN blocks will be entirely different.
Except that they were almost certainly using ANSI PIN blocks which XOR the card number into the data before encryption so that two identical PINs do not encrypt to the same cipher block. In addition, the terminals may have been using DUKPT, which is short for Derived Unique Key Per Transaction. This means that each PIN block is encrypted with a different key. Brute forcing one PIN block will not yield any information about the next one.
You have obviously never had to try and remove a broken bulb by futzing around in the socket with pliers to extract the pieces of bulb and socket and hoping that the circuit breakers really DID remove power from that circuit.
And that's precisely why kickstarter and indiegogo are so awesome. You see what the project wants upfront. You lose no money if the required amount is not reached. People digging into the details of the project can post about it, and you can read their warnings.
Indiegogo has a slightly slimier feeling option on their projects where the project gets to keep the money regardless of whether they meet their funding goal or not. If you are supporting a project on Indiegogo and this matters to you, be sure to check out the conditions on funding the project.
What if I don't reach my funding goal?
If your campaign is set up as Flexible Funding, you will be able to keep the funds you raise, even if you don't meet your goal. If your campaign is set up as Fixed Funding, all contributions will be returned to your funders if you do not meet your goal. Flexible Funding campaigns that meet their goal are only charged 4% as our platform fee, whereas campaigns that do not meet their goal are charged 9%.
Timothy, Timothy, Timothy. When will you ever learn? "Ask Slashdot" posts belong in the "Ask Slashdot" section so that those of us who choose to filter out those stories can do so. It doesn't work though if you keep posting "Ask Slashdot" stories in other sections.
Who wants to buy from a website for something big - who do I take it back to if it breaks? One of Amazon's "trusted partners"?
Have you bought something big from a traditional retail outlet lately? Once it's out the door it's no longer their problem. Have an issue? Call the manufacturer. Warranty claim? Call the manufacturer. It's really no different.
I am not labelling the majority of individual US citizens as sadistic, egotistical, greedy, sociopathic, controlling, corrupt, stupid and dishonest. Just the US nation as a whole (i.e. your government, your spies and the business and banking leaders and their "top people".)
I actually love my country. It's just the current government that runs it that turns my stomach.
And Timmy strikes again by not posting an Ask Slashdot story to the Ask Slashdot section. Hey Timmy! They put those sections there and allow readers to filter by section for a reason. Quit being a fucking tool and post the stories properly. In other words, do your job.
The OP is surprised why you can't find gifts that do this. The answer is simple: it's patented. No one in the USA is safe to produce this kind of effect without being sued, and the major photo publishers must be quite aware of this patent status and are not willing to pay the extra cost for the feature.
TextSecure's upcoming iOS client (and Android data channel client) uses a simple trick to provide asynchronous messaging while simultaneously providing forward secrecy.
At registration time, the TextSecure client preemptively generates 100 signed key exchange messages and sends them to the server. We call these "prekeys". A client that wishes to send a secure message to a user for the first time can now:
Connect to the server and request the destination's next "prekey."
Generate its own key exchange message half.
Calculate a shared secret with the prekey it received and its own key exchange half.
Use the shared secret to encrypt the message.
Package up the prekey id, the locally generated key exchange message, and the ciphertext.
Send it all in one bundle to the destination client.
The user experience for the sender is ideal: they type a message, hit send, and an encrypted message is immediately sent.
The destination client receives all of this as a single push notification. When the user taps it, the client has everything it needs to calculate the key exchange on its end, immediately decrypt the ciphertext, and display the message.
With the initial key exchange out of the way, both parties can then continue communicating with an OTR-style protocol as usual. Since the server never hands out the same prekey twice (and the client would never accept the same prekey twice), we are able to provide forward secrecy in a fully asynchronous environment.
Depending on how it's implemented, the whole system may depend on a central server that facilitates the initial key exchange (prekeys).
From the WhisperSystem posting:
The Cyanogen team runs their own TextSecure server for WhisperPush clients, which federates with the Open WhisperSystems TextSecure server, so that both clients can exchange messages with each-other seamlessly.
And Timmy strikes again by not posting an Ask Slashdot story to the Ask Slashdot section. Hey Timmy! They put those sections there and allow readers to filter by section for a reason. Quit being a fucking tool and post the stories properly. In other words, do your job.
Content remains scrambled as it traverses the Internet and is unreadable even to Syme, which stores the data on its servers. Co-founder Mullie authored a
white paper describing Syme's use of a two-step, hybrid encryption system that is fast, secure and efficient.
Apparently Soulskillet is taking posting lessons from Timothy by not posting an Ask Slashdot story to the Ask Slashdot section. Hey Soulskillet! They put those sections there and allow readers to filter by section for a reason. Quit being a fucking tool and post the stories properly. In other words, do your job.
Slashdot Mirror
In this case it does because it makes PIN blocks encrypted using the same working key be completely different. This prevents someone from performing a chosen plaintext attack by setting their own PIN to be 0000 or 1234 and comparing the captured PIN block to others. More of a limited rainbow table I guess.
Take a look at DUKPT, short for Derived Unique Key Per Transaction, to better understand how a PIN pad can be loaded with a set of keys that the merchant does not know. Similarly many PIN pads support remote key loading where asymmetric encryption is used to send a random 'working' 3DES key to the terminal. That key will be periodically replaced with a new one. Again the merchant has no idea what key is being used by the terminal at any given time.
Fortunately the PIN block encryption is salted. Please see my other post for the details.
PIN blocks are encrypted using PIN block format 0. In this format a portion of the account number is XORed with the PIN block prior to encryption. The result is that for two different accounts with the same PIN, even if they are encrypted with the same key, the resulting encrypted PIN blocks will be entirely different.
Except that they were almost certainly using ANSI PIN blocks which XOR the card number into the data before encryption so that two identical PINs do not encrypt to the same cipher block. In addition, the terminals may have been using DUKPT, which is short for Derived Unique Key Per Transaction. This means that each PIN block is encrypted with a different key. Brute forcing one PIN block will not yield any information about the next one.
You have obviously never had to try and remove a broken bulb by futzing around in the socket with pliers to extract the pieces of bulb and socket and hoping that the circuit breakers really DID remove power from that circuit.
That's what a potato is used for.
This might be the worst "summary" I've ever seen on slashdot.
The biggest problem is that I keep being able to honestly say this every day.
Considering it doesn't work on the beta it seems likely that Apple has already patched whatever hole they used.
I don't have a device to try it on, but the included readme.txt says
SUPPORTED FIRMWARES:
- iOS 7.0, 7.0.1, 7.0.2, 7.0.3, 7.0.4, 7.1beta1, 7.1beta2
And that's precisely why kickstarter and indiegogo are so awesome. You see what the project wants upfront. You lose no money if the required amount is not reached. People digging into the details of the project can post about it, and you can read their warnings.
Indiegogo has a slightly slimier feeling option on their projects where the project gets to keep the money regardless of whether they meet their funding goal or not. If you are supporting a project on Indiegogo and this matters to you, be sure to check out the conditions on funding the project.
From Indiegogo's FAQ.
What if I don't reach my funding goal? If your campaign is set up as Flexible Funding, you will be able to keep the funds you raise, even if you don't meet your goal. If your campaign is set up as Fixed Funding, all contributions will be returned to your funders if you do not meet your goal. Flexible Funding campaigns that meet their goal are only charged 4% as our platform fee, whereas campaigns that do not meet their goal are charged 9%.
Timothy, Timothy, Timothy. When will you ever learn? "Ask Slashdot" posts belong in the "Ask Slashdot" section so that those of us who choose to filter out those stories can do so. It doesn't work though if you keep posting "Ask Slashdot" stories in other sections.
What is your favorite novel that you have ever read? Favorite short story?
Who wants to buy from a website for something big - who do I take it back to if it breaks? One of Amazon's "trusted partners"?
Have you bought something big from a traditional retail outlet lately? Once it's out the door it's no longer their problem. Have an issue? Call the manufacturer. Warranty claim? Call the manufacturer. It's really no different.
I'm curious. How are labor unions in the EU organized/ran compared to those in the US?
I am not labelling the majority of individual US citizens as sadistic, egotistical, greedy, sociopathic, controlling, corrupt, stupid and dishonest. Just the US nation as a whole (i.e. your government, your spies and the business and banking leaders and their "top people".)
I actually love my country. It's just the current government that runs it that turns my stomach.
And Timmy strikes again by not posting an Ask Slashdot story to the Ask Slashdot section. Hey Timmy! They put those sections there and allow readers to filter by section for a reason. Quit being a fucking tool and post the stories properly. In other words, do your job.
The OP is surprised why you can't find gifts that do this. The answer is simple: it's patented. No one in the USA is safe to produce this kind of effect without being sued, and the major photo publishers must be quite aware of this patent status and are not willing to pay the extra cost for the feature.
Citation needed please.
The TextSecure Protocol
TextSecure's upcoming iOS client (and Android data channel client) uses a simple trick to provide asynchronous messaging while simultaneously providing forward secrecy.
At registration time, the TextSecure client preemptively generates 100 signed key exchange messages and sends them to the server. We call these "prekeys". A client that wishes to send a secure message to a user for the first time can now:
Connect to the server and request the destination's next "prekey."
Generate its own key exchange message half.
Calculate a shared secret with the prekey it received and its own key exchange half.
Use the shared secret to encrypt the message.
Package up the prekey id, the locally generated key exchange message, and the ciphertext.
Send it all in one bundle to the destination client.
The user experience for the sender is ideal: they type a message, hit send, and an encrypted message is immediately sent.
The destination client receives all of this as a single push notification. When the user taps it, the client has everything it needs to calculate the key exchange on its end, immediately decrypt the ciphertext, and display the message.
With the initial key exchange out of the way, both parties can then continue communicating with an OTR-style protocol as usual. Since the server never hands out the same prekey twice (and the client would never accept the same prekey twice), we are able to provide forward secrecy in a fully asynchronous environment.
Depending on how it's implemented, the whole system may depend on a central server that facilitates the initial key exchange (prekeys).
From the WhisperSystem posting:
The Cyanogen team runs their own TextSecure server for WhisperPush clients, which federates with the Open WhisperSystems TextSecure server, so that both clients can exchange messages with each-other seamlessly.
Here's a link to a single page version of the article.
And Timmy strikes again by not posting an Ask Slashdot story to the Ask Slashdot section. Hey Timmy! They put those sections there and allow readers to filter by section for a reason. Quit being a fucking tool and post the stories properly. In other words, do your job.
Actually I'm still wondering if the drone would be smart enough to land on pavement or miss entirely and drop packages on a customer roof or balcony
Hopefully they don't use the code that delivers care packages in Call of Duty then.
What could possibly go wrong?
Content remains scrambled as it traverses the Internet and is unreadable even to Syme, which stores the data on its servers. Co-founder Mullie authored a white paper describing Syme's use of a two-step, hybrid encryption system that is fast, secure and efficient.
I would prefer a non-car analogy please. It's been a while since the last good one.
Ok, if you were Peter Parker then ...
Apparently Soulskillet is taking posting lessons from Timothy by not posting an Ask Slashdot story to the Ask Slashdot section. Hey Soulskillet! They put those sections there and allow readers to filter by section for a reason. Quit being a fucking tool and post the stories properly. In other words, do your job.