arca_enc Files

arca version 4.15 - encryption engine supporting AES, Aria, Camellia, SM4,
ChaCha20, and TripleDES

12 July 2026

Files:
arca - Linux binary
arca.exe - Windows static binary
readme.txt - this file

The binaries are written in Crystal

Arca is a basic encryption engine, it's meant to be wrapped, but it can also be
used as stand alone command line encryption.


Command line:
usage: arca [options]

Enter "arca" without any options for help


* The keystream is derived from a combination of bcrypt / and sha512 hashing
<iter> times using the user supplied password and runtime supplied salt.

* The salt is derived from bcrypt using a uint64 generated from a rnd to seed.


Dana Booth <danabooth@mail.com>


CHANGELOG (releases only)

4.14
Allows for truncated command line options (--ciper and --method)

4.13
--shred and --delete original, among other things.

3.08
Added 3des for legacy sake, no other change in function.

3.05
Added some command line verification checking.

3.04
Added an options parser to make it more friendly when using it on the command
line.

3.02
Does file hash verification on deciphered files. As this increases the size of
the metadata, it again renders previous versions incompatible.

2.21
Added a bcrypt step to keystream generation. This is the first time I've
uploaded to Sourceforge for some time, and v2.21 is incompatible with earlier
versions.

2.18
Modified salt and IV generation.

2.11
Modified keystream generation, allowing for very large iterations.

2.08
Files retain original time stamp. Not sure why this never occurred to me
before. This effects compatibility with earlier versions due to the encrypted
file now containing metadata.

2.07
Reduced slice size from 16384 to 4096, does not affect compatibility with
earlier versions.

2.04
No change in function, just cleaning up.

1.02
Just internals, condensing code.

1.01
No change in function, first release version.