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A comment on Hacking a VW Golf Power Steering ECU. Parent comment

Re:Hacking a VW Golf Power Steering ECU by j4hdufd8 on Monday January 03, 2022 @11:00AM (#29782073)
> XOR with very large keys is how critical military encryption systems such as radios work.

Cool! Do you have any references?

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Re:Hacking a VW Golf Power Steering ECU by chrisseaton on Monday January 03, 2022 @11:08AM (#29782185)
For example the TETRA standard for trunked radio, "The key stream bits shall be modules 2 added (XORed) with plain text bits in data, speech and control channels".
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Re:Hacking a VW Golf Power Steering ECU by fanf2 on Monday January 03, 2022 @12:58PM (#29783860)
In the TETRA specification they use the term “key stream” to mean the output of a stream cipher, which they call a “key stream generator”. They aren’t XORing directly with a large key - the TETRA key size is 80 bits. See section 6.3.2.2 of https://www.etsi.org/deliver/etsi_en/300300_300399/30039207/...
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Re:Hacking a VW Golf Power Steering ECU by chrisseaton on Monday January 03, 2022 @01:14PM (#29784073)
Yes you can programatically generate a key.
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Re:Hacking a VW Golf Power Steering ECU by marcan_42 on Monday January 03, 2022 @01:24PM (#29784224)
And we call that a stream cipher, not "XOR encryption", even though it uses a XOR operation. You're programmatically generating a keystream, which is not the same thing as a key.
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Re:Hacking a VW Golf Power Steering ECU by ncmncm on Monday January 03, 2022 @02:10PM (#29784920)
See, this is why we can't have secure things.
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