Making backup's suggestion

[notlist3d]

I compress the wallet.dat file with 7 zip using encryption, then back up the files into usb disk. Is 7 zip encryption safe?

AFAIK, 7zip, WinRar, WinZip, etc. have all been cracked already. But as long as the wallet.dat file is encrypted you should be good.

No, 7zip's encryption is not cracked. I highly doubt WinRar and WinZip's are cracked either, but I don't use them. 7zip uses AES encryption, which is still not cracked. It is the safest encryption method as of today.

Just read into it. Apparently both have changed (a few years ago they were all cracked -- AES wasn't added until 7zip 3.x).

Keep them "cold" have on a few thumbdrives or sd cards or something that is not online.  You cannot crack what you cannot get to.  This is for wallets with sizable amounts.

If it's for low spending yes this is overkill.  But the part about being offline is very important if storing lots of coins.

[favdesu]

you could even extract the private keys and save them via keepass2 on a truecrypted usb stick. I consider this pretty secure.

[Zosinburg]

I compress the wallet.dat file with 7 zip using encryption, then back up the files into usb disk. Is 7 zip encryption safe?

AFAIK, 7zip, WinRar, WinZip, etc. have all been cracked already. But as long as the wallet.dat file is encrypted you should be good.

No, 7zip's encryption is not cracked. I highly doubt WinRar and WinZip's are cracked either, but I don't use them. 7zip uses AES encryption, which is still not cracked. It is the safest encryption method as of today.

Just read into it. Apparently both have changed (a few years ago they were all cracked -- AES wasn't added until 7zip 3.x).

Does it mean 7Zip 9.xx is not crackable? 7Zip has several compression method with difference compression ratio. Are they all not crackable?

[achow101]

Does it mean 7Zip 9.xx is not crackable? 7Zip has several compression method with difference compression ratio. Are they all not crackable?

Compression and encryption are different things. Compression does not encrypt anything, so anyone can decompress and read the data. The encryption that 7Zip uses is AES, which is still uncracked, so yes it is uncrackable.

[virtualx]

Can i put all my trust on only the "wallet.dat" file?  How do people usually make usb copies
I picked 2 usb copies because 1 usb might fail.

Don't forget to make copies of your private keys.  You can find it in "Tools -> Export private keys -> Epoxrt to (select file) -> Export private key". If you want you can password protect the key.

If the wallet.dat file is corrupted you could still import private keys.

[larem]

Can i put all my trust on only the "wallet.dat" file?  How do people usually make usb copies
I picked 2 usb copies because 1 usb might fail.

Don't forget to make copies of your private keys.  You can find it in "Tools -> Export private keys -> Epoxrt to (select file) -> Export private key". If you want you can password protect the key.

If the wallet.dat file is corrupted you could still import private keys.

To add on, the only time you WOULDN'T want to pass protect the private key is if you're writing it down and need to read it.