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LC4: Another Pen-and-Paper Cipher

Interesting symmetric cipher: LC4:

Abstract: ElsieFour (LC4) is a low-tech cipher that can be computed by hand; but unlike many historical ciphers, LC4 is designed to be hard to break. LC4 is intended for encrypted communication between humans only, and therefore it encrypts and decrypts plaintexts and ciphertexts consisting only of the English letters A through Z plus a few other characters. LC4 uses a nonce in addition to the secret key, and requires that different messages use unique nonces. LC4 performs authenticated encryption, and optional header data can be included in the authentication. This paper defines the LC4 encryption and decryption algorithms, analyzes LC4’s security, and describes a simple appliance for computing LC4 by hand.

Almost two decades ago I designed Solitaire, a pen-and-paper cipher that uses a deck of playing cards to store the cipher’s state. This algorithm uses specialized tiles. This gives the cipher designer more options, but it can be incriminating in a way that regular playing cards are not.

Still, I like seeing more designs like this.

Hacker News thread.

Posted on May 3, 2018 at 6:42 AMView Comments

NIST Issues Call for "Lightweight Cryptography" Algorithms

This is interesting:

Creating these defenses is the goal of NIST’s lightweight cryptography initiative, which aims to develop cryptographic algorithm standards that can work within the confines of a simple electronic device. Many of the sensors, actuators and other micromachines that will function as eyes, ears and hands in IoT networks will work on scant electrical power and use circuitry far more limited than the chips found in even the simplest cell phone. Similar small electronics exist in the keyless entry fobs to newer-model cars and the Radio Frequency Identification (RFID) tags used to locate boxes in vast warehouses.

All of these gadgets are inexpensive to make and will fit nearly anywhere, but common encryption methods may demand more electronic resources than they possess.

The NSA’s SIMON and SPECK would certainly qualify.

Posted on May 2, 2018 at 6:40 AMView Comments

IoT Inspector Tool from Princeton

Researchers at Princeton University have released IoT Inspector, a tool that analyzes the security and privacy of IoT devices by examining the data they send across the Internet. They’ve already used the tool to study a bunch of different IoT devices. From their blog post:

Finding #3: Many IoT Devices Contact a Large and Diverse Set of Third Parties

In many cases, consumers expect that their devices contact manufacturers’ servers, but communication with other third-party destinations may not be a behavior that consumers expect.

We have found that many IoT devices communicate with third-party services, of which consumers are typically unaware. We have found many instances of third-party communications in our analyses of IoT device network traffic. Some examples include:

  • Samsung Smart TV. During the first minute after power-on, the TV talks to Google Play, Double Click, Netflix, FandangoNOW, Spotify, CBS, MSNBC, NFL, Deezer, and Facebook­even though we did not sign in or create accounts with any of them.
  • Amcrest WiFi Security Camera. The camera actively communicates with cellphonepush.quickddns.com using HTTPS. QuickDDNS is a Dynamic DNS service provider operated by Dahua. Dahua is also a security camera manufacturer, although Amcrest’s website makes no references to Dahua. Amcrest customer service informed us that Dahua was the original equipment manufacturer.
  • Halo Smoke Detector. The smart smoke detector communicates with broker.xively.com. Xively offers an MQTT service, which allows manufacturers to communicate with their devices.
  • Geeni Light Bulb. The Geeni smart bulb communicates with gw.tuyaus.com, which is operated by TuYa, a China-based company that also offers an MQTT service.

We also looked at a number of other devices, such as Samsung Smart Camera and TP-Link Smart Plug, and found communications with third parties ranging from NTP pools (time servers) to video storage services.

Their first two findings are that “Many IoT devices lack basic encryption and authentication” and that “User behavior can be inferred from encrypted IoT device traffic.” No surprises there.

Boingboing post.

Related: IoT Hall of Shame.

Posted on May 1, 2018 at 6:32 AMView Comments

Security Vulnerabilities in VingCard Electronic Locks

Researchers have disclosed a massive vulnerability in the VingCard eletronic lock system, used in hotel rooms around the world:

With a $300 Proxmark RFID card reading and writing tool, any expired keycard pulled from the trash of a target hotel, and a set of cryptographic tricks developed over close to 15 years of on-and-off analysis of the codes Vingcard electronically writes to its keycards, they found a method to vastly narrow down a hotel’s possible master key code. They can use that handheld Proxmark device to cycle through all the remaining possible codes on any lock at the hotel, identify the correct one in about 20 tries, and then write that master code to a card that gives the hacker free reign to roam any room in the building. The whole process takes about a minute.

[…]

The two researchers say that their attack works only on Vingcard’s previous-generation Vision locks, not the company’s newer Visionline product. But they estimate that it nonetheless affects 140,000 hotels in more than 160 countries around the world; the researchers say that Vingcard’s Swedish parent company, Assa Abloy, admitted to them that the problem affects millions of locks in total. When WIRED reached out to Assa Abloy, however, the company put the total number of vulnerable locks somewhat lower, between 500,000 and a million.

Patching is a nightmare. It requires updating the firmware on every lock individually.

And the researchers speculate whether or not others knew of this hack:

The F-Secure researchers admit they don’t know if their Vinguard attack has occurred in the real world. But the American firm LSI, which trains law enforcement agencies in bypassing locks, advertises Vingcard’s products among those it promises to teach students to unlock. And the F-Secure researchers point to a 2010 assassination of a Palestinian Hamas official in a Dubai hotel, widely believed to have been carried out by the Israeli intelligence agency Mossad. The assassins in that case seemingly used a vulnerability in Vingcard locks to enter their target’s room, albeit one that required re-programming the lock. “Most probably Mossad has a capability to do something like this,” Tuominen says.

Slashdot post.

Posted on April 30, 2018 at 6:02 AMView Comments

TSB Bank Disaster

This seems like an absolute disaster:

The very short version is that a UK bank, TSB, which had been merged into and then many years later was spun out of Lloyds Bank, was bought by the Spanish bank Banco Sabadell in 2015. Lloyds had continued to run the TSB systems and was to transfer them over to Sabadell over the weekend. It’s turned out to be an epic failure, and it’s not clear if and when this can be straightened out.

It is bad enough that bank IT problem had been so severe and protracted a major newspaper, The Guardian, created a live blog for it that has now been running for two days.

The more serious issue is the fact that customers still can’t access online accounts and even more disconcerting, are sometimes being allowed into other people’s accounts, says there are massive problems with data integrity. That’s a nightmare to sort out.

Even worse, the fact that this situation has persisted strongly suggests that Lloyds went ahead with the migration without allowing for a rollback.

This seems to be a mistake, and not enemy action.

Posted on April 27, 2018 at 6:00 AMView Comments

Two NSA Algorithms Rejected by the ISO

The ISO has rejected two symmetric encryption algorithms: SIMON and SPECK. These algorithms were both designed by the NSA and made public in 2013. They are optimized for small and low-cost processors like IoT devices.

The risk of using NSA-designed ciphers, of course, is that they include NSA-designed backdoors. Personally, I doubt that they’re backdoored. And I always like seeing NSA-designed cryptography (particularly its key schedules). It’s like examining alien technology.

EDITED TO ADD (5/14): Why the algorithms were rejected.

Posted on April 25, 2018 at 6:54 AMView Comments

Computer Alarm that Triggers When Lid Is Opened

Do Not Disturb” is a Macintosh app that send an alert when the lid is opened. The idea is to detect computer tampering.

Wired article:

Do Not Disturb goes a step further than just the push notification. Using the Do Not Disturb iOS app, a notified user can send themselves a picture snapped with the laptop’s webcam to catch the perpetrator in the act, or they can shut down the computer remotely. The app can also be configured to take more custom actions like sending an email, recording screen activity, and keeping logs of commands executed on the machine.

Can someone please make one of these for Windows?

Posted on April 24, 2018 at 6:04 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.