SlowMist: Qubic Wallet leaked private keys via network headers

SlowMist found that Qubic Wallet built 55-character seeds with non-cryptographic Math.random(), and the same random stream filled the dejaVu header sent over plaintext TCP. Six captured header values let researchers rebuild the PRNG state in 15 ms and derive private keys. Qubic earlier reported about 2.94 trillion QU drained from 1,404 wallets.

• Seeds used Math.random() with at most 64 bits of entropy instead of 258.5
• The dejaVu header traveled over plaintext TCP after TLS at the web bridge
• Six header values enabled PRNG recovery in 15 ms via the Z3 solver
• About 2.94 trillion QU was drained from 1,404 wallets