Pick the large file.
Open the Encrypt flow and select the file. You do not need to split it, compress it, or move it anywhere first. Size is not a special case in AgePony 3.1.
// guide / encrypt-a-large-file
How to encrypt a very large file.
There is no special procedure. AgePony 3.1 streams the file in chunks with bounded memory, so nothing is held in RAM and a 1 GB video behaves like a 10 KB note. It just takes longer, and you get a progress bar for that.
// at a glance
- Open AgePony, choose Encrypt
- Pick the large file
- Choose a recipient or passphrase
- Watch the progress bar
- Share the .age file
Prerequisites
- AgePony 3.1 or later (current release is 3.1.0)
- Enough free space for the encrypted copy
- A recipient public key or a passphrase
Choose a recipient.
Add one or more recipient public keys (age or SSH), or switch to passphrase mode. This is the same recipient picker as any other file.
Watch the progress bar.
AgePony reads and encrypts the file in chunks and writes as it goes, which is why memory use stays flat instead of climbing with file size. The progress bar tracks real work, so on a big file it is worth leaving the screen open until it finishes.
Share the result.
You get a normal .age file. Send it, upload it, or keep it. Any standard age implementation reads it, whatever size it is.
Passphrase mode and the work factor
If you are using a passphrase rather than a recipient key, AgePony 3.1 lets you adjust the scrypt work factor in Settings. A higher work factor makes a stolen file much harder to attack by guessing passphrases, at the cost of more time and more memory every time you encrypt or decrypt. On a device with less memory to spare, lowering it keeps large-file work comfortable. Raise it when the file matters more than the wait.
Note
Decrypting, signing and verifying stream the same way. Large files behave consistently across all four operations, not just encryption.
Verify it worked.
- The progress bar runs to completion without the app being killed.
- The .age file is roughly the size of the original plus a small header.
- Decrypting it back returns a file identical to the original.
- Memory pressure warnings do not appear, even on a 1 GB input.
Common questions.
Is there a file size limit?
Nothing imposed by AgePony. Since 3.1 the file is streamed in chunks with bounded memory, so the practical limit is free space on your device.
Does the whole file load into memory?
No. AgePony 3.1 introduced bounded-memory streaming, so memory use stays flat whether the file is 1 MB or 1 GB.
What is the scrypt work factor for?
It controls how hard a passphrase is to guess by brute force. A higher work factor costs more time and memory on every encrypt and decrypt but resists guessing better. It is adjustable in Settings, which helps on devices with less memory to spare.
Do decrypt, sign and verify stream too?
Yes. Decrypting, signing and verifying use the same streaming path, so large files behave the same way in those flows.
Next steps.
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