If you need easy way to encrypt and decrypt files on linux systems, one way you can go is to use openssl, usually it is available on most servers,

Encyrpt:

openssl aes-256-cbc -iter 1000 -salt -e -in file.zip -out file.enc
pass:{password}

Decrypt:

openssl aes-256-cbc -iter 1000 -salt -d -in file.enc -out file.zip
pass:{password}

You should also be able to use it with des3, but I haven’t tested the fallowing:

Encrypt:

openssl des3 -salt -in file-plain.txt -out file-encrypted.txt.des3

Decrypt:

openssl des3 -d -salt -in file-encrypted.txt.des3 -out file-plain.txt