Bitcoin may not have been high on the agenda of Web Summit 2014, but a number of companies expressed an interest in the subject and even announced imminent involvement with digital currency.

The tech conference, which has grown from 400 to 20,000 attendees in four years, had seven 'stages', spanning digital marketing to sports and entertainment, along with a roster of high-profile speakers. These included Dropbox founder Drew Houston, actress Eva Longoria and and skateboarding legend Tony Hawk.

Bill Ready, chief executive of payments processor Braintree, which also operates the popular mobile wallet Venmo, spoke at the event. He said bitcoin could be one of several payment modes in a "multi-wallet world".

He told the audience:

Speaking to CoinDesk, Ready stressed that he saw bitcoin as "complementary" to mobile wallets and that it would co-exist with other payment methods including credit and debit cards.

Payment processor PayCash announced at the conference that it would allow merchants in Europe to take bitcoin payments, following a partnership with Kraken, an established exchange for euro-bitcoin trading.

Another European payments firm, Adyen, also told CoinDesk it was working on bitcoin integration, which could launch next year.

Looking outside of payments, the founder of digital signature company DocuSign, Tom Gonser, told CoinDesk his firm was experimenting with bitcoin and blockchain technologies in its research and development lab. Notably, DocuSign counts financial institutions like GE Capital and First American Bank among its customers.

Gonser pointed to bitcoin's decentralised nature as having the potential to change the way digital identities are secured in the future.

Yoni Assia, chief executive of Etoro, extolled bitcoin's worth as an asset class, calling it "digital gold". Etoro is a "social trading" platform, allowing users to trade bitcoin 'contracts for difference', a type of derivative.

Assia said: "Bitcoin is disrupting both technology and financial markets. It's the new global currency ... people refer to it as the TCP/IP of value."

He added:

The Bitcoin Foundation's chief scientist Gavin Andresen took to the event's 'Centre Stage' today, speaking with the Wall Street Journal's Lisa Fleisher, about centralisation in bitcoin mining, regulation and the future of digital currency.

On the subject of regulation, he said: "Getting regulatory clarity is really important. In the last year, year and a half, we've seen more regulatory clarity. I think it's been incredibly positive for bitcoin, but now we need regulation that isn't going to kill innovation."

Andresen wasn't the only member of the bitcoin community present at the summit – several bitcoin companies had booths at the event, including BitPay, BitMEX and SpectroCoin. Executives of bitcoin firms such as Circle were also seen in attendance.

Featured image via Flickr.