Bug 1709867 Comment 1 Edit History

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It might be worthwhile to implement 3 levels of spoofing:

1. UTC (this is the current RFP behaviour)
2. inspired by [brave #8574](https://github.com/brave/brave-browser/issues/8574), do not spoof the timezone offset (like UTC+3 remains UTC+3) but simplify the timezone name (like `America/Toronto` becomes `America/New York`; that is, pick the most popular timezone name in that timezone offset.)
3. no spoofing

(2) is interesting because it looks like it will unbreak a lot of functionality while not leaking too much entropy (for instance, fingerprintjs [uses timezone name](https://github.com/fingerprintjs/fingerprintjs/blob/b412d8c5eba1072dced47f98ff7a7dcaa81b6829/src/sources/timezone.ts#L3-L16) for fingerprinting). See, also, [my proof-of-concept patch](https://github.com/sgmenda/ideas/tree/main/simplify-timezones-to-resist-fingerprinting).

If it is possible, it would be nice to make (2) the default, but I am worried that it might cause non-trivial breakage (if we get a chance, we should measure this).
It might be worthwhile to implement 3 levels of spoofing:

1. UTC (this is the current RFP behaviour)
2. inspired by [brave #8574](https://github.com/brave/brave-browser/issues/8574), do not spoof the timezone offset (like UTC+3 remains UTC+3) but simplify the timezone name (like `America/Toronto` becomes `America/New York`; that is, pick the most popular timezone name in that timezone offset.)
3. no spoofing

(2) is interesting because it looks like it will unbreak a lot of functionality while not leaking too much entropy (for instance, fingerprintjs [uses timezone name](https://github.com/fingerprintjs/fingerprintjs/blob/b412d8c5eba1072dced47f98ff7a7dcaa81b6829/src/sources/timezone.ts#L3-L16) for fingerprinting). See, also, [my proof-of-concept patch](https://github.com/sgmenda/ideas/tree/main/simplify-timezones-to-resist-fingerprinting).

If it is possible, it would be nice to make (2) the default in Firefox, but I am worried that it might cause non-trivial breakage (if we get a chance, we should measure this).

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