Windows tool to protect a text file with sensitive data

Question

I need a Windows tool to encrypt a text file with sensitive data. I want to keep the file online.

Ideally one that can decrypt the .gpg (binary) and .asc (base64) outputs of gpg4win.

I came across SafePad (claims to use AES-256) and EncryptPad (OpenPGP). Would like a pro/con comparison of these two please.

Answer 1

Difference between AES-256 and OpenPGP

First, I want to clarify that AES-256 and OpenPGP are not mutually exclusive. It's simpler to look at OpenPGP as wrapper for data encrypted with AES-256 symmetric cipher. OpenPGP format specification also tells how to store encryption parameters in the file including the cipher AES-256, Hash algorithm, salt, iterations and others. Below is the list of features that OpenPGP provides:

1. Encrypted data (encrypted with AES-256 if you choose so).
2. Encryption parameters
3. Compression
4. Integrity verification to ensure that the data has not been damaged or tampered.

Applications and OpenPGP

Both gpg4win and EncryptPad follow the same format specification called RFC 4880. They are compatible with limitations:

1. EncryptPad only supports symmetric encryption. So files encrypted with asymmetric (private and public keys) will not open in EncryptPad.

2. EncryptPad does not support .asc format. You need to dearmor files before they can be opened with EncryptPad:

   gpg --dearmor -o binary_file.gpg asc_file.asc

This requires both products to be installed gpg4win and EncryptPad.

3. EncryptPad provides a subset of gpg4win. All gpg files saved by EncryptPad can be opened in gpg4win.

Difference between GPG4WIN and EncryptPad

1. gpg4win is a professional tool with main purpose of transferring data to remote recipient with whom you don't have prearranged secrets.

2. EncryptPad is for storage of documents and binary files in encrypted form and transferring data to somebody with whom you prearranged a secret.

3. gpg4win has its own code (which can be provided as a library called libgcrypt) that implements the security algorithms of the AES-256, key derivation and so on. EncryptPad relies on Botan for that while having its own OpenPGP implementation.

EncryptPad and SafePad

1. EncryptPad is implemented in C++. It supports the three main platforms: Windows, Linux and macOS. SafePad is implemneted with .NET 4.5, which is primarily Windows Framework. However it's possible to make it run on other platforms with help of extra tools.

SafePad has also been tested and works under Linux with the Mono Runtime.

The SafePad issue tracker has an open question about the platform compatibility.

2. EncryptPad follows RFC4880 specification, which is compatible with gpg4win. SafePad format seems to rely on the underlying .NET library.