I’m not sure what you are concerned about in particular in the context of traveling to these places. I have lived in Korea for over 12 years, so I will share my two cents.

In another comment someone has said this:

Both countries have highly invasive laws and will demand access to many things.

In all my time living here, I have never ever had the government “demand access” to my things, and I have never heard of this happening to anyone traveling here. In the times I visited China, however, ALL of my things were ALWAYS searched at the airport (plus telecommunication itself is just a fucking nightmare there). Even going to Japan I was always flagged for extra searches, but never Korea. I am not sure what they mean by “demand access” but I think they have overstated a bit, or don’t really know how it is here. If you commit crimes while you are here, then of course, like pretty much the rest of the world, you can expect to be interrogated, and depending on the nature of that crime, your stuff could get seized and searched (but it is not the case that any run-in with the cops will result in them cloning your hard drives or anything like that. There is a lot of red tape around that, so unless there is good reason to do so, no one will go through the trouble).

Korea does not have great laws about privacy, and people are mostly ambivalent about it. The main “privacy-offending” thing about Korean digital culture is that your citizenID is linked to your online accounts (not all of course). So, if you have a blog on Naver, you can be anonymous to readers of that blog (as in you can use whatever handle you like), but if, for example, you are doing illegal things on that blog then the police can easily identify you. For a foreigner visiting here on tour, this is all irrelevant. If you register as an alien (for work or study etc.) then you may end up making accounts here, but you are not really obligated to…and it is not the case that ANYTHING you do online must be tracked by the Korean government or anything like that. I have blogs, gemlogs, phlogs etc. scattered all around the internet. The Korean government will in no way seek those out to surveil me, let alone try to control or censor what I do there. Their operation is just not that focused, and it is out of their jurisdiction anyway. It just doesn’t work like that. Of course, if you break laws here, then expect to be investigated. But there is no law saying you cannot have overseas accounts or whatever.

It is not the case that everyone is constantly subjected to 1984-style surveillance and totalitarian oppression. If that is what you fear, then don’t go to China. As far as surveillance goes, I would say Austraila is actually worse (based on what I have gleaned from the news). Overall, the main concerns I have about privacy here are the same that apply everywhere: apps, services, operating systems slurping up as much of your data as possible and selling it etc. However, Korea has adopted GDPR-esque laws that require Korean companies to notify you when your data has been provided to a third party, or requested by the government. If you are just visiting, you probably don’t really have a reason to sign up with Korean service providers, and in some cases you will not be able to unless you have a visa (other than a tourist visa).

If you are worried about your internet browsing being surveilled, don’t be (like I said, it is not much different from most other places in the world). Some sites are “blocked” by ISPs, mostly porn sites and North Korea propaganda sites, but this is nothing tor cannot circumvent. There is no “great firewall” like in China, and in fact, the blocked sites can all still be accessed by using a DNS provider other than the Korean ISP itself. But tor or a VPN is the easiest way. VPNs are not illegal, tor is not illegal. No one gives a shit and most people don’t even know what these are.

There are CCTV cameras all over the place, but the vast majority of these are not involved in facial recognition or anything like that. There are some of those in place out in the wild, but they are actually pretty rare and controversial. To me, the main problem about privacy here is that people just don’t even think about it. So for example, when COVID first hit, the government was providing data to the public about where infected people went (not their identities but their movements). So there were cases where some wives found out their husbands were visiting brothels, etc. It was a weird lack of oversight that resulted from the general ambivalence about privacy here.

I don’t know if this helps at all. If you are considering visiting here then I recommend that you do. Korea is a very interesting place, and usually people who visit kind of fall in love with it. As far as privacy is concerned, it is nothing like China at all. Although, I also recommend visiting China just because it is a fascinating place too! If there is anything in particular you are concerned about privacy-wise, let me know and maybe I can give you some perspective on it.

As with most things privacy related, it depends on your threat model. A journalist may be scrutinized more than a regular tourist. If you’re going for business that involves trade secrets, you’ll also need to be extra careful with your data.

For China, yes it’s good advice to be a little paranoid with privacy. Just get a vpn before traveling and keep it on at all times. Don’t connect your phone to random usb ports like in your hotel room. Be aware of what wifi spots you connect to and try to limit personal activity online (i.e. logging on to banking, social media, etc.) unless necessary. Only bring in data that you need (i.e. don’t take an external drive of photos that you don’t need). Reset all passwords of the accounts you logged in to when you get back.

SK is fine for a regular tourist. Just take general precautions and you should be fine. Again, it depends on your threat model.

All you privacy is gone no matter where you go or where you live.

it already is.

YES you should not bring any technological devices with you. In fact it is better to abstain from digital systems for a period of 3 months before entering and after leaving China. (Viruses, etc)

DO NOT think your anus is safe. I had a friend who tried to smuggle in 3tb of Xi Jinping x Winnie the Pooh fanfics by encrypting it with AES-1024 and storing it on micro SD cards in his rectum. Little did he know, that day they had started doing mandatory anus probes on all foreigners. They found it. They cracked the encryption in a few minutes due to Chinese quantum supremacy and needless to say, he was executed on spot.

DO NOT think about the CPC. They have theta-brainwave detectors at the border and can detect revisionist and counter-revolutionary thoughts. Especially if you have any information that could lead to the downfall of the CPC.

Seriously though, what are you expecting to happen? What privacy are you expecting to lose? What laws for discrimination are you expecting to be missing?

When you travel internationally you already lose some privacy in that they have your passport. You are telling them exactly who you are, and where you came from. Some countries will take fingerprint scans (US, China too). Those are pretty big but are not specific to China. You should disable biometrics on your phone though, as that means they cannot force you to unlock it. But regarding the tech on your phone, if you are using any google or meta services, then all your privacy is already gone and Chinese authorities can just buy that information if they want. So I’m not sure exactly what you’re worried about, some specifics might be useful.

It would also help to know what you want the cloud storage for. They can’t suddenly hack into all of your accounts the moment you cross the border. If you already have sensible security steps like strong passwords and MFA in place, then I don’t see what else you’d need to do.

Yes. Both countries have highly invasive laws and will demand access to many things.

DO Bring a completely clean and clear Burner Phone. Do not log into anything on it, do not download any apps, or sideload necessary apps when you can, do not do anything besides basic activation.

DO invest in personal private cloud storage but make sure it’s hosted somewhere SAFE and that you won’t have issues getting through the Great Firewall (China) to it. Make sure you paid up to host it for the duration of your stay BEFORE you leave your home country.

You are not freaking out! It’s perfectly fine to protect your privacy and it is NOT illegal. You cannot predict when or if you will have a run-in with local authorities in some countries. It’s best if those authorities have nothing to hold you on.

Having a clean, secure, and private device which does not leak any unnecessary information about you when seized is ideal.

You don’t even have to go that far.

Business people travelling to China are advised to take burner phones/laptops with limited access, in case the security services there attack them. I don’t know about South Korea.

if I was travelling abroad I would not be bringing anything that has universal access to my accounts or data (primary phone for example). I would most likely get a new device loaded only with what I needed to get things done using a new account I transferred money into. For the most part I would not expect any issues but the laws at most borders, even US international borders generally say they can clean you out of all your data and force you to log into any devices you have with you. So the 2 countries mentioned are only part of the story when it comes to privacy when travelling international.