Tag Archives: Internet

Great Internet Mersenne Prime Search

The Great Internet Mersenne Prime Search (GIMPS) is a collaborative project of volunteers who use freely available software to search for Mersenne prime numbers. The project was founded by George Woltman, who also wrote the software Prime95 and MPrime for the project. Scott Kurowski wrote the Internet PrimeNet Server that supports the research to demonstrate Entropia-distributed computing software, a company he founded in 1997. GIMPS is registered as Mersenne Research, Inc. Kurowski is Executive Vice President and board director of Mersenne Research Inc. GIMPS is said to be one of the first large scale distributed computing projects over the Internet for research purposes.[1]

The project has found a total of fourteen Mersenne primes as of 5 February 2013, eleven of which were the largest known prime number at their respective times of discovery. The largest known prime as of January 2013 is 257,885,161 − 1 (or M57,885,161 in short). This prime was discovered on January 25, 2013 by Curtis Cooper at the University of Central Missouri.[2]

To perform its testing, the project relies primarily on Édouard Lucas and Derrick Henry Lehmer‘s primality test,[3] an algorithm that is both specialized to testing Mersenne primes and particularly efficient on binary computer architectures. They also have a less expensive trial division phase, taking hours instead of weeks, used to rapidly eliminate Mersenne numbers with small factors, which make up a large proportion of candidates. John Pollard’s p − 1 algorithm is also used to search for larger factors.

On January 25th, prolific GIMPS contributor Dr. Curtis Cooper discovered the 48th known Mersenne prime, 257,885,161-1, a 17,425,170 digit number. This find shatters the previous record prime number of 12,978,189 digits, also a GIMPS prime, discovered over 4 years ago. The discovery is eligible for a $3,000 GIMPS research discovery award.

Dr. Cooper is a professor at the University of Central Missouri. This is the third record prime for Dr. Cooper and his University. Their first record prime was discovered in 2005, eclipsed by their second record in 2006. Computers at UCLA broke that record in 2008. UCLA held the record until Dr. Cooper and the University of Central Missouri reclaimed the world record with this discovery.

While Dr. Cooper’s computer found the record prime, the discovery would not have been possible without all the GIMPS volunteers that sifted through numerous non-prime candidates. GIMPS founder George Woltman and PrimeNet creator Scott Kurowski thank and congratulate all the GIMPS members that made this discovery possible.

Mersenne primes are extremely rare, only 48 are known. GIMPS, founded in 1996, has discovered the last 14 Mersenne primes. Mersenne primes were named for the French monk Marin Mersenne, who studied these numbers more than 350 years ago. Chris Caldwell maintains an authoritative web site on the history of Mersenne primes as well as the largest known primes.

The primality proof took 39 days of non-stop computing on one of the University of Central Missouri’s PCs. To establish there were no errors during the proof, the new prime was independently verified using different programs running on different hardware. Jerry Hallett verified the prime using CUDALucas running on a NVidia GPU in 3.6 days. Dr. Jeff Gilchrist verified the find using the standard GIMPS software on an Intel i7 CPU in 4.5 days. Finally, Serge Batalov ran Ernst Mayer’s MLucas software on a 32-core server in 6 days (resource donated by Novartis IT group) to verify the new prime.

You can read a little more in the short press release.

Start the program! (Linux and FreeBSD users should run the program from the command line with a -m switch, i.e. “./mprime -m”).  Enter your optional userID created on the website in Step 1, and optionally name your computer.  We recommend Windows users select Options, Start at Bootup or Start at Logon.
That’s all you need to do! The program contacts a central server called PrimeNet to get some work to do.  Usually the program and PrimeNet know the best work to assign, but it’s up to you!You can administer your account and computers on your userID’s account page. Once you complete a workunit you can track your standings on the competitive stats pages the server updates every hour (see Top Producers in the menu, left, for more stats). You can monitor each of your computers’ progress, even remote-control the work assignments they request using your userID’s CPUs page!

Linux and FreeBSD versions can also be set up to run every time you restart your computer. Ask for help at the Mersenne Forum.

Questions and Problems: Please consult the readme.txt file for possible answers. You can also search for an answer, or ask for help in the GIMPS forums. Otherwise, you will need to address your question to one of the two people who wrote the program. Networking and server problems should be sent to Scott Kurowski. Such problems include errors contacting the server, problems with assignments or userids, and errors on the server’s statistics page. All other problems and questions should be sent to George Woltman, but please consult the forums first.

Disclaimers: See GIMPS Terms and Conditions. However, please do send bug reports and suggestions for improvements.


Software Source CodeIf you use GIMPS source code to find Mersenne primes, you must agree to adhere to the GIMPS free software license agreement. Other than that restriction, you may use this code as you see fit.

The source code for the program is highly optimized Intel assembly language. There are many more-readable FFT algorithms available on the web and in textbooks. The program is also completely non-portable. If you are curious anyway, you can download all the source code (40.6MB). This file includes all the version 27.9 source code for Windows, Linux, FreeBSD, and Mac OS X. Last updated: December 12, 2012.

The GIMPS program is very loosely based on C code written by Richard Crandall. Luke Welsh has started a web page that points to Richard Crandall’s program and other available source code that you can use to help search for Mersenne primes.


Other available freewareAt this time, Ernst Mayer’s Mlucas program and Guillermo Ballester Valor’s Glucas program are the best choices for non-Intel architectures. Luke Welsh has a web page that points to available source code of mostly historical interest you can use to help search for Mersenne primes.

Nigerian email scams

Nigerian email scams have become nearly as commonplace as the Internet itself. But one Australian woman wound up in jail after turning the tables–to the tune of $30,000–on a group of con artists.
The Courier-Mail reports that Sarah Jane Cochrane-Ramsey, 23, was employed as an “agent” in March 2010 by the Nigerians, but didn’t know they were scam artists. Her “job” was to provide access to an Australian bank account opened in her name where the Nigerians could then transfer money they had received from a phony car sales website. Cochrane-Ramsey was told she could keep eight percent of the transfers.
But, then she decided to steal from the thieves themselves. According to the Courier-Mail, she received two payments, totaling $33,350, but spent most of it on herself.
If you’re not familiar with the so-called Nigerian Scam, also known as the (419) scam, or Advanced Fee Fraud, here’s a brief explainer: the fraud works by convincing an individual to give money and/or bank account access to a third-party in exchange for future financial rewards.
Most commonly, the scam artist will claim to be a wealthy Nigerian individual looking to move his vast financial resources to another country. He then promises the fraud victim a hefty payment in exchange for a temporary loan or bank account access in order to facilitate the move. Of course, the fraud victim never receives the promised payout and instead usually ends up losing thousands of dollars in the process. According to Scam Busters, the Advance Fee Fraud scams often target small businesses and charities. And while the scam has been around for years, the U.S. Financial Crimes Division of the Secret Service still receives a reported 100 calls a day from people claiming to be victims of a (419) crime.
But, back to the Cochrane-Ramsey case. The real victims who thought they were buying cars online reported the scam to the police, who traced the account back to Cochrane-Ramsey. She was ordered to appear in Brisbane District Court and plead guilty to one count of aggravated fraud.

For now, the court judge is allowing Cochrane-Ramsey time to come up with the money to pay off the fraud victims while she awaits sentencing in March.
Interestingly, Cochrane-Ramsey is not the first person to turn the tables on Nigerian scammers. In 2008, the radio program This American Life ran a story on some anonymous pranksters who sent a Nigerian scam artist on a wild goose chase that spanned 1,400-miles into war-torn Chad for a promised cash payout at a local Western Union branch.
And they convinced him to do this while carrying an anti-Muslim/pro-George W. Bush note, which stated his intention to rob the Western Union. Their entire plan was spelled out on this website, dedicated to turning the tables on Internet con artists (Warning: contains Not Safe for Work language).
You can listen to the episode of This American Life here.

Facebook passwords

SEATTLE (AP) — Two U.S. senators are asking Attorney General Eric Holder to investigate whether employers asking for Facebook passwords during job interviews are violating federal law, their offices announced Sunday.

Troubled by reports of the practice, Democratic Sens. Chuck Schumer of New York and Richard Blumenthal of Connecticut said they are calling on the Department of Justice and the U.S. Equal Employment Opportunity Commission to launch investigations. The senators are sending letters to the heads of the agencies.

The Associated Press reported last week that some private and public agencies around the country are asking job seekers for their social media credentials. The practice has alarmed privacy advocates, but the legality of it remains murky.

On Friday, Facebook warned employers not to ask job applicants for their passwords to the site so they can poke around on their profiles. The company threatened legal action against applications that violate its long-standing policy against sharing passwords.

A Facebook executive cautioned that if an employer discovers that a job applicant is a member of a protected group, the employer may be vulnerable to claims of discrimination if it doesn’t hire that person.

Personal information such as gender, race, religion and age are often displayed on a Facebook profile — all details that are protected by federal employment law.

“We don’t think employers should be asking prospective employees to provide their passwords because we don’t think it’s the right thing to do. While we do not have any immediate plans to take legal action against any specific employers, we look forward to engaging with policy makers and other stakeholders, to help better safeguard the privacy of our users,” Facebook said in a statement.

Not sharing passwords is a basic tenet of online conduct. Aside from the privacy concerns, Facebook considers the practice a security risk.

“In an age where more and more of our personal information — and our private social interactions — are online, it is vital that all individuals be allowed to determine for themselves what personal information they want to make public and protect personal information from their would-be employers. This is especially important during the job-seeking process, when all the power is on one side of the fence,” Schumer said in a statement.

Specifically, the senators want to know if this practice violates the Stored Communications Act or the Computer Fraud and Abuse Act. Those two acts, respectively, prohibit intentional access to electronic information without authorization and intentional access to a computer without authorization to obtain information.

The senators also want to know whether two court cases relating to supervisors asking current employees for social media credentials could be applied to job applicants.

“I think it’s going to take some years for courts to decide whether Americans in the digital age have the same privacy rights” as previous generations, American Civil Liberties Union attorney Catherine Crump said in a previous interview with the AP.

The senators also said they are drafting a bill to fill in any gaps that current laws don’t cover.

Maryland and Illinois are considering bills that would bar public agencies for asking for this information.

In California, Democratic Sen. Leland Yee introduced a bill that would prohibit employers from asking current employees or job applicants for their social media user names or passwords. That state measure also would bar employers from requiring access to employees’ and applicants’ social media content, to prevent employers from requiring logins or printouts of that content for their review.

In Massachusetts, state Democratic Rep. Cheryl Coakly-Rivera also filed a similar bill Friday that also expands to include personal email. Her measure also bars employers from “friending” a job applicant to view protected Facebook profiles or using similar methods for other protected social media websites.

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Manuel Valdes can be reached at https://twitter.com/ByManuelValdes.

Google Privacy Policy

We’re getting rid of over 60 different privacy policies across Google and replacing them with one that’s a lot shorter and easier to read. Our new policy covers multiple products and features, reflecting our desire to create one beautifully simple and intuitive experience across Google.
We believe this stuff matters, so please take a few minutes to read our updated Privacy Policy and Terms of Service at http://www.google.com/policies. These changes will take effect on March 1, 2012.
Got questions?
We’ve got answers.
Visit our FAQ at http://www.google.com/policies/faq to read more about the changes. (We figured our users might have a question or twenty-two.)

privacy on Internet

A new tool under development by Oregon State computer scientists could radically alter the way that communications work on the web. Privly is a sort of manifesto-in-code, a working argument for a more private, less permanent Internet.

The system we have now gives all the power to the service providers. That seemed to be necessary, but Privly shows that it is not: Users could have a lot more power without giving up social networking. Just pointing that out is a valuable contribution to the ongoing struggle to understand and come up with better ways of sharing and protecting ourselves online.

“Companies like Twitter, Google, and Facebook make you choose between modern technology and privacy. But the Privly developers know this to be false choice,” lead dev Sean McGregor says in the video below. “You can communicate through the site of your choosing without giving the host access to your content.”

Through browser extensions, Privly allows you to post to social networks and send email without letting those services see “into” your text. Instead, your actual words get encrypted and then routed to Privlys servers (or an eventual peer-to-peer network). What the social media site “sees” is merely a link that Privly expands in your browser into the full content. Of course, this requires that people who want to see your content also need Privly installed on their machines.