Work rejected. Server says: Stale or alien proof of work

1
...
0 0
2

One thing that strikes me about claims of alien visitation is that so much of the evidence is musty and fusty.

Every day, I get stories and articles from people around the world who aggregate UFO news. But much of it is not news — it’s olds. The folks who think there’s good proof that Earth is a stomping ground for extraterrestrials are still hung up on the Roswell incident of 1947 or its British opposite number, the Rendlesham Forest event of 1980. They’re still citing the testimony of aging politicians, defense establishment types and Apollo astronauts who “know something.”

The few alternatives to this vintage archive are contemporary photos and videos of vague lights in the sky, low-resolution and low-confidence material that isn’t likely to sway many scientists. The good stuff seems to be the old stuff.

To better judge if this is really true, I trawled the web for listings of “the best UFO cases.” I quickly collected nearly 100 events that were considered...

0 0
3

The Proof-of-Work in Cryptocurrencies: Brief History. Part 1

This is a guest post by Ray Patterson

Check our on comparing Proof of Work, Proof of Stake and other Proofs-of.

Before Bitcoin: Hashcash & Moderately Hard, Memory-bound Functions

The Proof-of-work concept appeared for the first time in the paper in 1993. Despite the fact that authors never used this notion in the article itself (it is 6 years before it appears), we are going to name it this way (or PoW).

So, what was the Idea proposed by Cynthia Dwork and Moni Naor in their paper?

The main idea is to require a user to compute a moderately hard, but not intractable, function in order to gain access to the resource, thus preventing frivolous use.

We can use the following parallel: the Ministry of Fishery makes do some work in order to access a local pond, e.g. plant a couple of trees and send the photos of plantlets. The important point is that Jeremy is able to perform...

0 0
4

Everyone who has looked at Bitcoin close enough probably understands that it’s a revolutionary achievement created by a legendary, forward thinking individual or group. Superficially, the revolutionary technology built within it has the ability to send money without any central authority, so you don’t need someone to issue your cash, it just exists – somewhat similar to gold.

But also, everyone who had time to dig a little deeper could see that Bitcoin technology goes far beyond money. Basically, what you have in Bitcoin is the first decentralized database in history, and value transfer is just one of many natural applications for it. A much broader range of data can be stored on the blockchain. Projects such as Couterparty, Tether, and Mastercoin utilize the decentralized nature of the Bitcoin blockchain database for a wide range of financial operations, including trading and crowdfunding.

Crypto 2.0 platforms, such as NXT, Eth, and Bitshares offer functionality...

0 0
5

One of the most secret and mysterious premises in the United States of America and possibly the world is Area 51; the US military base located about 80 miles northwest of Las Vegas. There are many claims that Area 51 has an underground facility where reverse engineering is being carried out on spacecrafts that allegedly belongs to aliens. The wreck of the much famed Roswell UFO Crash is believed to be kept in Area 51 where reverse engineering is being done on the craft. US Military and Federal government has always refuted the possibilities of these claims being true, but there are many evidences that certainly prove a strong connection between Area 51 and the aliens.

Unearthly happenings

(1) Area 51 is situated in the middle of the deserts of Nevada, and people from the nearby towns have reported sightings of strange lights which are seen hovering over the alleged alien investigation camp in Area 51. As per eye witnesses, the lights do not look like coming from...

0 0
6
Visualize and Download High-Resolution Infographic

A proof of work is a piece of data which was difficult (costly, time-consuming) to produce so as to satisfy certain requirements. It must be trivial to check whether data satisfies said requirements.

Producing a proof of work can be a random process with low probability, so that a lot of trial and error is required on average before a valid proof of work is generated. Bitcoin uses the hashcash proof of work.

One application of this idea is using hashcash as a method to preventing email spam, requiring a proof of work on the email's contents (including the To address), on every email.

Legitimate emails will be able to do the work to generate the proof easily (not much work is required for a single email), but mass spam emailers will have difficulty generating the required proofs (which would require huge computational resources).

Hashcash proofs of work are used in Bitcoin for block generation. Proofs of...

0 0
7

Markus Jakobsson and Ari Juels

Citation: Proofs of Work and Bread Pudding Protocols, In B. Preneel, ed., Communications and Multimedia Security, pages 258-272, Kluwer Academic Publishers, 1999.

Abstract: We formalize the notion of a proof of work (POW). In many cryptographic protocols, a prover seeks to convince a verifier that she possesses knowledge of a secret or that a certain mathematical relation holds true. By contrast, in a POW, a prover demonstrates to a verifier that she has performed a certain amount of computational work in a specified interval of time. POWs have served as the basis of a number of security protocols in the literature, but have hitherto lacked careful characterization. In this paper, we offer definitions treating the notion of a POW and related concepts.

We also introduce the dependent idea of a bread pudding protocol. Bread pudding is a dish that originated with the purpose of reusing bread that has gone stale. In the same spirit,...

0 0
8
...
0 0
9

Software design patterns are designed to solve specific problems with the right context, and if used inappropriately, they'll lead to extra unnecessary complexity without providing any values.

So, what are the problems that the repository pattern aims to solve?

1- Minimizing duplicate query logic: in large applications, you may find many complex LINQ queries duplicated in a few places. If that's the case, you can use the repository pattern to encapsulate these queries and minimise duplication.

2- Better separation of concerns: Imagine a complex query to get the top selling courses in a given category that involves eager loading, joining, grouping, filtering, etc.

When you implement such large complex queries in your services/controllers, you'll end up with fat services/controllers. These classes become hard to unit test as they'll require a lot of noisy stubbing. Your unit tests become long, fat, and unmaintainable.

If you're facing this problem,...

0 0
10

One of the ways to protect systems from denial of service attacks is increase the cost of attacking the system until either the attack is cost prohibitive or ineffective. One way of increasing the cost of an attack is to have the attacker perform work before servicing their requests. Proof of work can be useful for situations where legitimate requesters only make occasional requests, legitimate requesters have the resources to compute proof of work. For legitimate requesters not overloading the network, it should be relatively inexpensive for them to provide proof of work compared to attackers who must provide many times the proof of work.

Ripple uses proof of work to protect against some types of denial of service attacks. Additionally, rippled can be used as a proof of work server to create, solve, and verify challenges.

See also:

Proof of work can be demanded by a server when it accepts an incoming connection. When a server receives excessive suspicious...

0 0
11

When beginning work, new employees must produce, on their first day, EITHER:

NOTE: Must be original documents... photocopies are not acceptable.

List A

Documents that Establish Both Identity and Employment Eligibility

U.S. Passport (unexpired) Permanent Resident Card or Alien Registration Receipt Card (Form I-551) An unexpired Foreign passport that contains a temporary I-551 stamp or temporary I-551 printed notation on a machine-readable immigrant visa An unexpired Employment Authorization Document that contains a photograph (Form I-766) In the case of a nonimmigrant alien authorized to work for a specific employer incident to status, a foreign passport with Form I-94 or Form I-94A, bearing the same name as the passport and containing an endorsement...
0 0
12

System-wide data is available at the following locations:

/api/pool/stats - general pool statistics

An object with the following attributes:

/api/pool/hashrate - pool hash rate in Ghps

The pool hash rate (Ghps) as a plain number.

/api/pool/workers - active workers

The number of active workers as a plain number.

/api/pool/users - active users

The number of active users as a plain number.

/api/pool/round - status of current rounds

An object with the following attributes:

Each chain is an object with the following attributes:

/api/pool/blocks - latest blocks

Optional parameters:

Example with parameters: /api/pool/blocks?commodity=BTC&max=20 - 20 latest BTC blocks

Returned is an array of objects with the following attributes:

/api/pool/shifts - latest shifts

Optional parameters:

Example with parameters: /api/pool/shifts?max=20...

0 0
13

UFOs are real and, in fact, the aliens who traveled here in their interstellar flying discs now work for the United States government — according to a top aerospace scientist who died in August, but left behind an extraordinary deathbed interview in which he reveals his high-level, inside knowledge of the United States government’s UFO program.

Boyd Bushman won numerous patents while working for Lockheed-Martin, Hughes Aircraft and several other aerospace technology firms over a 40-year career. Bushman is also credited, according to some reports, with developing the Stinger missile, the shoulder-fired surface-to-air missile that has played a key role in numerous conflicts for the past three decades.

Bushman died on August 7. But not long before passing away, he gave an extraordinary interview which turned up on YouTube earlier this month and has already accumulated more than 1.1 million views.

Given the nature of the purported revelations in the video, it’s...

0 0
14

A stale share occurs when you find a share and submit it to the mining pool after the pool has already moved on to the next block. The percentage of stale shares should be very low if everything's working correct, around 2 out of 1,000 shares or so.

Several factors affect the stale share rate. The three most important are long polling, pool load, and miner-to-pool latency.

Any shares found based on old work units after the pool controller receives a new block will be stale. Long polling is a technique that allows the pool to notify all of its miners when there's a change in the block chain so they can immediately request new work units. If your pool or mining software doesn't support long polling, you will finish out the old work units, generating stale shares.

When the long polling notification goes out, all miners that support long polling request new work units at about the same time. This generates a massive burst of load as the pool has to manages lots of...

0 0
15

A proof of work is a piece of data which is difficult (costly, time-consuming) to produce but easy for others to verify and which satisfies certain requirements. Producing a proof of work can be a random process with low probability so that a lot of trial and error is required on average before a valid proof of work is generated. Bitcoin uses the Hashcash proof of work system.

One application of this idea is using Hashcash as a method to preventing email spam, requiring a proof of work on the email's contents (including the To address), on every email. Legitimate emails will be able to do the work to generate the proof easily (not much work is required for a single email), but mass spam emailers will have difficulty generating the required proofs (which would require huge computational resources).

Hashcash proofs of work are used in Bitcoin for block generation. In order for a block to be accepted by network participants, miners must complete a proof of work which...

0 0
16

Under the federal Immigration Reform and Control Act, new employees must present proof that they are legally authorized to work in the United States. When you take a new job, you are required to fill out the employee’s section of USCIS Form I-9 by the end of your first day on the job. You then have three business days to present your new employer with documents proving that:

you are who you say you are, and you are legally authorized to work in the United States.

If you use forged, counterfeit, or altered documents to prove your identification or authorization to work, you may be fined and even imprisoned.

When One Document Is Sufficient

United States Citizenship and Immigration Services (USCIS, formerly the INS) periodically updates the list of documents sufficient to prove both identity and eligibility to be employed in the United States. Any one of the following documents is sufficient, on its own, to meet the requirements:

an unexpired United...
0 0
17

A client recently switched to Exchange Server / Outlook for their email. Since then emails from my company to any email address at their company bounce back from the System Administrator with this error:

Your message did not reach some or all of the intended recipients. Subject: Email Solution Sent: 12/12/2012 11:08 AM The following recipient(s) cannot be reached: 'name@client.org' on 12/12/2012 11:08 AM 550 5.1.1 recipient rejected

Looking in the Message Options of the bounce back email shows no data in the Internet Header field.

My client's IT guy says we're not being blocked, but I cant think of any other reason the bounce would occur.

Any suggestions on what questions to ask or how to fix this would be helpful.

I'm using a desktop version of Outlook 2007 and connecting through my...

0 0