Cash is still the biggest competition for the growing number of digital payments companies and it will not go away anytime soon, according to the chief technology officer at PayPal.

Many companies are trying to create a digital payments economy but they face stiff competition from an existing mode of payment, according to Sri Shivananda, senior vice president and chief technology officer at PayPal.

“The competition is cash,” Shivananda told CNBC in an interview last month. “It’s not even, like, you’re fighting for each other’s volumes. It’s actually cash.”

Cash transactions still exceed digital payments even though they are not easy to manage, Shivananda said.

Last year, a study from consultancy giant Capgemini and bank BNP Paribas predicted that by 2020, people around the world would make about 726 billion transactions using digital payment technologies.

The study found that emerging markets are expected to drive the upward trend. Developments in new technologies such as contactless bank cards, wearable devices and augmented reality will drive cashless transactions in the future, according to the study.

Still, it acknowledged that cash remained the main method of payment among users. In fact, other research findings and surveys have demonstrated that many around the world still prefer to use cash.

Last August, a PayPal study found cash was still king in Asia, with China being an outlier where majority of the respondents said they preferred using digital payments. The European Central Bank said in November that a majority of people in the Euro area used cash when paying for goods and services in 2016 — especially for small-value items below 15 euros ($17.62).

Still, in recent years, new forms of online payments have emerged, including mobile wallets and cryptocurrencies.

But the move away from cash will take time and it would be the digital natives — people born after 1980 — who would lead the change, according to Shivananda.

“Their primary mode of interaction with everything in the world is digital,” he said.

Even then, it would not be easy to dislodge cash from society and move solely to digital payments, according to David Ng, a principal at investment firm B Capital Group’s Singapore office.

“Cash is going to be around for a bit, especially in many emerging markets,” Ng told CNBC. He explained that in many countries, it’s not easy to obtain credit or debit cards, or use digital payment platforms.

But a systematic push from governments and the availability of good digital payment platforms, like WeChat Pay and M-Pesa, might drive more people toward cashless transactions, he said. Even then, “consumers will still choose a hybrid of both,” he added.

There are three things that payments companies must do to convince people to make the jump from using cash to digital payments, according to Shivananda.

“Security is definitely number one,” he said. “Privacy is number two and reliability is number three.”

With cash, most transactions happen directly between a buyer and a seller and, therefore, is usually both secure and private. But with digital payments, users would want to know that, not only is their money secure, but the way they spend is also kept private, Shivananda explained.

That becomes a fine line which digital payments companies have to tread, because one benefit of digital payments include the ability for businesses to collect data that can give them insights into customer behavior.

Being a reliable payments service is therefore a competitive advantage for companies, said the experts.

“It is often hard for consumers and merchants to distinguish who has a better technology,” B Capital’s Ng said. “But they will make their judgment based on ease of use, performance and network.”

Fraudulent online transactions, data breach and privacy issues would likely erode user trust in digital payments and other financial technology — or fintech — services, according to experts.

Scott Galit, CEO of Payoneer, a payments processing company based in New York, added that some fintech companies today underestimate issues surrounding regulation, risk and compliance.

That may potentially increase the risk of events, such as a cyber attack, where consumer trust is destroyed because a start-up did not follow anti-money laundering procedures, according to Galit.

“Overall, I think there’s too much tech, not enough fin,” he said, adding, “Most of the people that get into this don’t come from the financial services side. They come at it with a ‘oh, I can be a disruptor’ [and] use technology to do some cool stuff.”