SlowMist: Qubic Wallet Has Security Vulnerability; Private Key Could Be Recovered Through 6 Consecutive Network Observations

On October 20, the SlowMist security team discovered during an analysis of the Qubic wallet that when generating account seeds and the dejaVu identifier values published in network packet headers, the wallet shared the same non-cryptographically secure random number stream (Math.random()), potentially exposing private keys to recovery via network observation.

The potential attack path indicates that an attacker could collect dejaVu identifier values from node communications, use six consecutive observations to calculate and recover the state of the 128-bit pseudorandom number generator, thereby reconstructing the 55-character account seed. This could then be verified using the public key exposed in balance requests, ultimately allowing the attacker to recover the private key and forge SchnorrQ signatures to transfer assets.

SlowMist has confirmed the technical feasibility of this recovery chain through a proof of concept, while noting that actual exploitation depends on factors such as network trust boundaries and observation continuity. The team recommends using cryptographically secure random number generators for key generation and conducting comprehensive security audits.