Yannblog

The personal website of Ian Littman

MASC: Miniature/Modifiable Asymmetric-Symmetric Cryptosystem

May 8

Posted by Ian Littman in General | No Comments

I just finished writing my final report for Intro to Modern Cryptography. The topic: a light, home-brewed, C++, library-asisted OpenPGP equivalent for encrypting files. The basic concept is as follows for OpenPGP:

  1. Symmetric encryption (AES etc.) is fast but you have to get the key from point A to point B securely
  2. Asymmetric encryption (RSA etc.) negates the key sharing requirement but is slow
  3. Asymmetrically encrypt a symmetric “session” key, then use the session key to encrypt the file/message you’re trying to send and you get the best of both worlds!

So I made a command line utility, using the Chilkat Visual C++ library set, that did the above for file encryption, with automatic signing built in so the recipient knows who sent the file. The application is rather basic, but it works very well (and pretty quickly for encryption/decryption…my IdeaPad took about seven seconds each to encrypt and decrypt a 100MB file) and is easy to dissect for anyone who wants to do that sort of thing.

For more information, download the package below Read the rest of this entry »

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Page Updates, Class Elections

Apr 13

Posted by Ian Littman in General | No Comments

So I finally updated my About page and my Google profile to reflect where I am now, rather than where I was six-plus months ago. Or thereabouts.

I should also note that I ran for Student Body President here at Mines. This isn’t the first time I’ve run for such a position; I ran last year for Junior Class Treasurer (a friend was running for Junior Class President and I didn’t want to split the ticket), and in fall 2007 I ran for Freshman Class President. This is the first time I was soundly defeated; the other two positions were won by a handful of votes by my opponent. Read the rest of this entry »

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Looking back on today’s communications outage

Mar 23

Posted by Ian Littman in Tech | 3 Comments

UPDATE 4: Added a Kerrville Daily Times link for a new article on how 911 is handled. Lots of good information there.

UPDATE 3: Added another news source. Swamped by homework so tweets will have to wait, but other than those I think I’ve got all the online info on the outage linked from here.

UPDATE 2: Added another couple of news sources, corrected one of my usual typos…some how I forgot to add a “not” into the paragraph about Wal-Mart taking credit card transactions. Sorry for the confusion. Also modified information based on an article from the Fredericksburg Standard Radio-Post. The link below takes you to the subscriber-only version of the article; the non-subscriber snippet just makes the paper look bad (very little info).

UPDATE: Added some more news articles, (still) working on collecting all tweets about the incident, revised some information for accuracy (originally wasn’t sure about CricKet and Pocket, but they too were taken down by the outage…DSL was also apparently iffy in Kerrville).

Granted, I wasn’t in the area when it happened, but since I have plenty of family and friends down there I’m certainly going to talk about it! Read the rest of this entry »

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If the iPad can do this stuff, I’ll buy it

Jan 30

Posted by Ian Littman in General | 1 Comment

So the 3G version of the iPad (announced Wednesday) is still three months away, but I already have some expectations that, if met, would cause me to fork over $630 for the sucker…these expectations are realistic technology-wise, though I’m pretty sure they would require a jailbreak to get working…

1. SIP VoIP, over 3G and WiFi, with Bluetooth and in the background
I’ve successfully run phone calls over AT&T’s HSPA network, so assuming the processor on the iPad is “all that” this shouldn’t be difficult. If I can get a SIP client that connects to a Bluetooth headset and allows other applications “up front” without killing voice quality then I’ve got a very versatile system for nformation gathering while “on the phone.” This is particularly useful when you see my other requests below:

2. Full-fledged RDP, SSH and VNC clients…and either GoToMyPC or LogMeIn if at all possible
The iPad can be an excellent remote access tool; its screen has enough resolution to run any modern OS without having to scroll around. Add in the keyboard accessory and you’ve got a lovely little remote terminal that works anywhere AT&T has service (I’m talking about the 3G version here). Or any other non-AWS GSM or 3G carrier for that matter; the device is unlocked. SSH would be a godsend for doing command line heavy lifting, though you’d need a host to SSH to in this case (not a big deal for me). Even nicer, all of the above will likely be available for the iPad as App Store apps; no jailbreaking required.

3. A high-quality PDF viewer
I want a PDF viewer that can search and copy text, preferably at least as good as Preview. Yes, Preview can be outdone with PDFs…it’s not the most compatible piece of PDF reader in the world unfortunately. Read the rest of this entry »

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Verizon WIreless – A Quick Test

Jan 11

Posted by Ian Littman in General | 3 Comments

So up until now I’ve tested three of the four providers who have 3G service in Fredericksburg, TX: AT&T, Sprint and CricKet, listed in order of connection speed, descending. I was able to borrow a Verizon aircard from work (Novatel USB727) and check Verizon’s speed at my house. Here are the results: Read the rest of this entry »

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My experience with GVTC

Dec 22

Posted by Ian Littman in General | No Comments

So I’m headed down to South Padre Island for some downtime with the family before Christmas. We made a pit stop at the Flagstop Café and my mom noticed that there was a big sign in the window advertising the availability of WiFi.

So naturally I pulled out my HTC Touch Pro, which has WiFi, to see what network they were running on. After registering for an account on the hotspot provider (Less Networks, never heard of them) I checked whatismyip.com to see who I was on. Sure enough, the connection there was GVTC, registered as “Guadalupe Valley Telephone”. Right before we pulled out of the place I opened up my laptop, logged into the WiFi network that way and did some tests. Read the rest of this entry »

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Force 3G on a Sierra Wireless aircard on a Mac…here’s how

Oct 17

Posted by Ian Littman in General | 1 Comment

So I bought an AT&T data plan earlier today. SIM-only, no contract. Pretty cool, since their less-than-a-month-old 3G network around here is still pretty speedy. I didn’t need an aircard as I purchased a Sierra Wireless USBConnect 881 back during the days of “unlimited” GoPhone data for $20. The card lay dormant after “unlimited” became 100MB (big difference) but today it meant the difference between signing a contract (aka not getting service) and not signing one.

One problem arose when I got home: my aircard kept switching to EDGE during the middle of a data session. Not a good thing for a $60 + taxes and fees data plan. So I needed to force 3G on the card. The problem there was that only the Windows Sierra and AT&T clients allow forced 3G. So (not knowing that settings are stored on the modem and thus once I set 3G-only on my Windows computer it would be 3G-only on my Mac) I scrounged around and found this page. I followed those instructions and was able to make sure my aircard was 3G-only.

If you don’t want to read through a (relatively short) page on how to kick your aircard into high gear, you’re in luck. Here’s what you’d do on a Mac to force-3G a Sierra aircard. Note that this procedure was performed on OS X 10.6.1 and with the Apple “native” driver installed (a tiny download from here). This is also with the latest modem firmware, which I had to use the Sierra driver (vs. the native one) to upgrade to.

  1. Go to Terminal (Applications > Utilities)
  2. Type in screen /dev/tty.wwanCMD 115200 and hit enter.
  3. Type in AT!band? and hit enter.
  4. If you see the number 02, you’re already locked into 3G-only mode. Otherwise, type in AT!band=02 and hit enter to set the mode. If you wanted to go 2G-only, the code would be 04 instead of 02. AUtoselect is 00.

Hope this helps! Now I’m cooking along with 2-3 bars of signal (-87 dBm right now) and pulling down these speeds:

Though connection quality is quite a bit more variable than Sprint’s (slower, particularly on uploads) connection at my place…

In comparison, SPrint usually pulls down 1.3 Mbps down, 300-500 kbps up and gets a B on connection quality.

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