Dan GoodinJun 13, 2023

Researchers have devised a novel attack that recovers the secret encryption keys stored in smart cards and smartphones by using cameras in iPhones or commercial surveillance systems to video record power LEDs that show when the card reader or smartphone is turned on.

The attacks enable a new way to exploit two previously disclosed side channels, a class of attack that measures physical effects that leak from a device as it performs a cryptographic operation. The first attack uses an Internet-connected surveillance camera to take a high-speed video of the power LED on a smart card reader—or of an attached peripheral device—to pull a 256-bit ECDSA key off a government-approved smartcard. The other allowed the researchers to recover the private SIKE key of a Samsung Galaxy S8 phone by training the camera of an iPhone 13 on the power LED of a USB speaker connected to the handset.

https://arstechnica.com/information-technology/2023/06/hackers-can-steal-cryptographic-keys-by-video-recording-connected-power-leds-60-feet-away/

Hackers can steal cryptographic keys by video-recording power LEDs 60 feet away

Key-leaking side channels are a fact of life. Now they can be done by video-recording power LEDs.

Ars Technica
Show threadPoroCYon

@dangoodin interesting attack but uh

SIKE has been cryptographically broken (see https://en.wikipedia.org/wiki/Supersingular_isogeny_key_exchange ), it actually takes more time to pull off this side channel attack than break the cryptography & find the keys

Supersingular isogeny key exchange - Wikipedia

Jun 13, 2023 at 5:04pmWeb
Show threadDan GoodinJun 13, 2023

@pcy I think you're being too literal here. The SIKE key retrieval is a PoC that shows that video recording a power LED can, in fact, leak a key of substantial size. Keep in mind, this technique will likely be useful in exploiting side channels discovered in the future that affect algorithms that haven't been deprecated. Also, you do know that I reported on the demise of SIKE back in August and noted it again in this article, yes?

I notice also that you make no mention of the key retrieval for ECDSA, which is still widely in use.