“There was a shipping delay,” says one customer review, “but the vendor was honest and clear about the issue. I haven’t tried the product yet but based on past experience I’m confident in the quality.” Another agrees: “It came way faster than expected too. I was expecting arrival later this week and was startled to hear my doorbell but pleasantly surprised to see my package.”

Customers of last week’s Black Friday being positive in their praise of product quality and customer service? Or clients of a new parcel-delivery service impressed having tried it for the first time? Not even close.

These are just two of 57 online reviews posted on the profile of an ecstasy dealer selling drugs not on a street corner or in a nightclub but on the darknet.

It is the secretive underbelly of the internet, where users are anonymous and where everything and anything is for sale. Looking for a consignment of counterfeit cigarettes or fake branded sporting gear? No problem. Maybe you’re in the market for a high-quality fake passport, a gun, fake currency, cloned and stolen credit cards, ivory or even rhino horns?

In this online store some of humanity’s most awful products are traded. It is also where many photographs and videos of child sex abuse are found.

Cannabis by post

The growth is also due to the apparent professionalisation of the trade. It's impossible to determine how much of the drug trade has moved online, but indicative data for Ireland suggests that it's a growing phenomenon. Figures obtained by The Irish Times reveal that cannabis was discovered in the postal service – at sorting centres – 640 times last year. That was more than the previous four years combined and more than a tenfold increase on the 60 seizures in 2011.

Seizures of other illegal drugs in the postal service, especially psychoactive substances once available in headshops but now banned, also suggest a buoyant and increasing online trade.

The Lisbon-based European Monitoring Centre for Drugs and Drug Addiction, in a report earlier this year, said that in 120 of 129 samples of online drug purchases, the “drug that customers thought they had purchased was the only psychoactive substance detected”. Cocaine bought online was 70 per cent pure, compared with the average 38 per cent purity of street-purchased cocaine in the UK in 2013.

The new type of online drug dealer is “also likely to be relatively free from the violence typically associated with traditional drug markets”, the report notes. “In the drug cryptomarket era, having good customer service and writing skills and a good reputation via feedback as a vendor or buyer may be more important than muscles and face-to-face connections.”

And, most of all, it is growing because of the simplicity of the process. So how easy is it to get on to the darknet and take part in this illegal online trade? The Irish Times went exploring to find out.

Tor, the “onion router”

The darknet is accessed using the Tor – or “onion router” – browser. It was developed by the US navy and launched in 2004 as a way to remain anonymous online. Although it has been used for spying and by dissidents in countries with repressive regimes, criminals were quick to adapt the secret network for its own purposes.

Tor works by bouncing data all over the world and adding layers of encryption as it goes, like the skin of an onion, creating anonymity. It also conceals users’ IP addresses and server locations. It means buyers and sellers in all of the shady marketplaces are anonymous, their identities and locations concealed not only from each other but also from international law enforcement.

To get on to Tor I first visit TorProject.org on the surface web and download the browser; it takes a couple of minutes, and it’s free and perfectly legal. Once installed, the browser sits on my desktop alongside my Internet Explorer and Firefox icons. With the means to proceed with a drug purchase, now I need to know where to look. A number of vast online directories have become reference sources for users of the darknet. Hosted on the surface web and completely legal, they contain links to sites on the darkweb. I find these directories easily and plump for one of the many drug-marketplace sites.

Unlike the surface web, the website’s address or URL bears no resemblance to the site’s name. It looks like a jumble of letters and numbers with “.onion” at the end.

I click on the link and am asked to register and create a profile from which to order and pay for goods. I can then proceed to the site; its name and logo across the top confirm that I’m at my destination.

TripAdvisor for drug deals

Under my new user name I can leave reviews, recommend “vendors” (better known as drug dealers) who have proved reliable, or warn against sellers of poor-quality products – or product that never arrives, always a risk on the darknet. It’s like an Airbnb or TripAdvisor for drug deals.

Users are invited to shop for products and services under the headings Fraud, Drugs & Chemicals, Guides & Tutorials, Counterfeit Items, Digital Products, Jewels & Gold, Weapons, Carded Items, Services, Malware & Software, and Security & Hosting. A click on each section throws up an even larger subindex. The Drugs & Chemicals button leads to a 13-option index of drug types.

This one site lists almost 200,000 drugs and chemical items. The busiest section, Cannabis & Hashish, contains more than 55,000 items or lots for sale. Also included are sections for benzodiazepines, dissociatives, ecstasy, opioids, prescription drugs, steroids, stimulants, tobacco, weight loss, paraphernalia and psychedelics.

I click the ecstasy button, which is broken down into a further six-option index offering types of MDMA, or methylenedioxymethamphetamine. Prices vary, depending on quantity, but the average going rate seems to be just under $3 a pill. One dealer is offering 20 tablets a deal, claiming that each contains pill 200mg of MDMA – roughly twice as pure as ecstasy pills sourced on the street. The dealer says that the pills carry “no risk of brain lesions, no comedown, stay trippy, stay safe”.

The approach to the customer is similar to that of conventional retailers. The site not only allows tracking of orders and customer reviews but also rates vendors on the basis of how much product they have sold and how trustworthy their reviewers say they are.

If a preferred vendor is out of stock you can set an alarm that notifies you when the goods are available again. You can also message vendors directly.

I tap in a quantity of pills and am asked to pay. Instead of a conventional payment card, buyers pay with Bitcoin, the virtual online currency that can also be used to buy regular goods and services, from coffees to cinema tickets.

The currency is not regarded as illegal by the Irish authorities. There is at least one Bitcoin ATM in Ireland, where Bitcoin can be cashed in and withdrawn in euro. Bitcoin can be bought on the surface web, using a debit or credit card, on sites that are legal and easy to find. A system called tumbling ensures that your Bitcoin purchases cannot be connected to you.

Of course you must have your drugs delivered, and there is no way to do this other than specify an address.

Many of the buyer reviews suggest that those involved had simply used their home addresses and hoped that their drug-concealing parcels would make it to them. Others book PO boxes or postal lockers in “parcel motels”.

Online reviewers rate the quality of “stealth”, or concealment, meaning only those darknet dealers who become expert packers will continue to attract customers. Although the address must be printed clearly on the outside of a package for postal delivery, it is encrypted on the darknet, meaning that no record of it is floating around cyberspace.

The Irish Times does not proceed with the darknet purchase. In this article we have omitted the addresses of directories and sites that would reveal details of how the purchase worked.

Sniffer dogs

Although browsing these sites, downloading software and using Bitcoin are legal, buying banned substances on darknet sites is a criminal office. Those caught doing so face prosecution and possible jail terms. The drugs themselves are also illegal, for good reasons: many carry huge health hazards and addiction risks.

Our research though makes clear the ease with which people are now purchasing illegal drugs online.

Sniffer dogs are the darknet drug trade’s biggest enemy, but with a limited number of animals and handlers working in sorting offices around the world, including Ireland, a huge volume of contraband is reaching its destination undetected.

In this changing world, imaginative policing and detection techniques are needed to stem the growth of this trade.