New Attack Breaks Textbook RSA in Record Time
Researchers from UC San Diego and Inria Nancy have developed an attack that cracks textbook RSA keys faster, but it requires many queries and only affects the raw variant.
A new paper from researchers at UC San Diego and Inria Nancy outlines an attack that breaks RSA encryption in record time, significantly reducing the number of operations needed to crack keys of 1024, 2048, 3072, and 4096 bits. The findings, reported by tomshardware.com, are pending peer review.
The attack specifically targets the textbook or raw variant of RSA, which is used in services such as Cloudflare Privacy Pass, iCloud Private Relay, and Private Cloud Compute. It also affects PKCS #11 equipment like smart cards, USB security tokens, code-signing pipelines, HSMs, and TPMs.
However, the attack requires an exceedingly high number of queries against the targeted key's oracle, making it impractical for many real-world scenarios. The researchers tested the attack on Thales Luna HSMs in both hardware and online service forms.
The algorithms used are far from optimized and could be sped up with optimization, AI tools, and GPUs, potentially making the attack more efficient in the future.
Quick answers
What is textbook RSA?
Textbook RSA is the raw variant of RSA encryption without padding, used in services like Cloudflare Privacy Pass and iCloud Private Relay.
Does this attack affect all RSA implementations?
No, it only works against the textbook or raw variant of RSA, not padded versions.
Has the research been peer-reviewed?
No, the findings are pending peer review.