The team has built a tool to test for bit flips
in a target system to check how vulnerable it is to this attack method, dubbed Throwhammer, and expect to make it publicly available in the near future.
If there is a single bit flip
at any node of the circuit, the corruption in the intermediate parity will propagate to the output, which will eventually cause a mismatch between input and output parities.
Four different simulated fault injection (based on bit flip) techniques are conducted.
Parity check code is one of the simplest error detecting codes that can be used to detect single bit error and odd number of bit flips .
Working with Bellcore's Boneh and Richard DeMillo, Lipton showed in principle how random bit flips
could be exploited to deduce the secret key in the RSA cryptographic scheme when used in a smart card.
Repeatedly accessing a row in recent DRAM devices can cause bit flips
in adjacent rows, and attacks demonstrated and documented by the Google Project Zero team have used this behavior to gain kernel privileges on x86-64 Linux machines (from unprivileged user-land).
Reportedly, a microprocessor in the 737 Max wasn't sufficiently protected against the consequences of random bit flips
(a 0 changing to a 1, for instance).
The first one included attacks that caused bit flips
and the second one cropping and removal attacks causing missing bits.
NASA and Boeing are among the organizations who devote considerable engineering efforts to the "hardening" of electronic devices designed to operate in harsh environments to protect them against random bit flips
, singe event upsets in semiconductor chips due to cosmic rays or naturally-occurring radioactive elements in packaging materials.
About one bit flips
per every 1,000 to 2,500 instructions copied, adding variation to the daughter cell.