A claim has emerged that concerns over bitcoin's security against quantum computers are limiting inflows from institutional investors.

On Oct. 27, Cointelegraph reported that Muneeb Ali (무니브 알리), co-founder of Stacks, a bitcoin-based layer2 smart-contract network, said bitcoin needs a credible upgrade roadmap to transition to quantum-resistant security to regain investor trust.

In an interview on Cointelegraph's "Chain Reaction" podcast, Ali said, "Because of concerns about quantum computers, bitcoin's growth already has a ceiling." He explained that risk-averse institutional investors could postpone large bitcoin purchases until developers present a concrete path to move to quantum-resistant security.

He warned that if developers fail to make meaningful progress on the transition to quantum-resistant security by 2028, bitcoin could enter a riskier phase. He said upgrades typically take years to implement, and users then need time to move their holdings to new addresses.

Ali cited guidance from the U.S. National Institute of Standards and Technology (NIST) and suggested 2030 as a target time to shift to a quantum-resistant security system. He also said the timeline could be brought forward to 2029 if advances in artificial intelligence accelerate quantum-computer development.

Some bitcoin supporters believe the quantum-computing threat is still far off and related concerns are exaggerated. Ali said that the disagreement itself over how urgent the threat is could erode investor confidence, and stressed the importance of creating a credible upgrade plan.

The quantum-computing threat may not be limited to bitcoin. Ali said, "If bitcoin takes a hit, everything else below it also takes a hit." That means projects developing their own security measures may find it difficult to avoid the shock caused by bitcoin security issues.

He said a sufficiently powerful quantum computer is more likely to emerge first at major research institutions than from an unidentified attacker. He added that companies such as Google or Microsoft (MS) would have to accept legal liability if they stole bitcoin, giving them little incentive to do so.

The industry is also developing countermeasures. StarkWare said in September its researchers cut by 79 percent the estimated computational cost needed to prepare an experimental quantum-resistant bitcoin transaction through a week of optimization work. The approach does not require changing bitcoin's consensus rules, but the cost-reduction effect has so far been confirmed only in benchmark tests.

StarkWare described the technology as a last resort, while maintaining that a protocol-level upgrade is needed over the long term. When and how bitcoin developers present a concrete plan for transitioning to quantum-resistant security is seen as a factor that will affect institutional investor confidence and market participation.