Despite blockchain's corporate buzz this year, the technology can be tricky to get exposure to as an investor, unless you're buying bitcoin.

To give clients some less controversial options, J.P. Morgan named three public companies who are potential long-term winners in the emerging technology.

The firm predicted software companies will use blockchain in a similar way to how many currently claim the benefit of machine learning and artificial intelligence. But there are few that J.P. Morgan says will create "material incremental growth opportunities" from the technology.

"Investors should be looking to identify where the opportunity to replace a middleman is the biggest, or where trust is needed where none exists, or what companies are the best positioned to offer blockchain as a service," J.P. Morgan software equity research analyst Sterling Auty said in a note to clients Thursday.

J.P. Morgan's bets for that disruption are "middleman displacement opportunities" and "Blockchain as a Service," which the firm calls "BaaS." In the bank's coverage at least three names fit that criteria — Akamai, DocuSign and Ellie Mae.

Cloud service provider Akamai, rated "overweight" by J.P. Morgan, could leverage the "BaaS" approach.

"Rather than building from scratch we see customers looking to utilize a vendor like Akamai that offers its Blockchain capabilities as a service," Auty said. "While there are a number of companies that have blockchain technology, IBM as one example, we believe the sizeable Akamai network is an inherent advantage in running a distributed ledger in blockchain."

In this case, J.P. Morgan is advocating for use of closed, permissioned blockchain, also known as just "private." Bitcoin by comparison, is the biggest "public" blockchain meaning anyone can join or participate in that network. Its "distributed ledger," where transactions are recorded can also be seen by just about anyone.

DocuSign already offers the ability to connect a blockchain network to its systems. The company, which J.P. Morgan also rated "overweight," could leverage both private and public blockchains.

"DocuSign wants to be the platform to enable the entire contracting process in a digital manner. Over time we could see much of the platform being based on blockchain, basically shifting its

centralized security model for the distributed model of blockchain," J.P. Morgan's Auty said.

Auty called real estate the most "obvious" use case for blockchain technology. Ellie Mae, which J.P. Morgan has an "underweight" rating on, stands to benefit as a result.

"Utilizing blockchain to manage the entire mortgage process could bring trust among parties and use of smart contracts could help automate various tasks (inspection, income/employment verification," Auty said.