Some easy bash scripts to encrypt/decrypt data, for anyone who wants to go all cloak&dagger. (bitcoin private keys, etc.)

encrypt_decrypt.sh

# Encryption functions. Requires the GNUpg "gpg" commandline tool. On OS X, "brew install gnupg"
# Explanation of options here:
# --symmetric - Don't public-key encrypt, just symmetrically encrypt in-place with a passphrase.
# -z 9 - Compression level
# --require-secmem - Require use of secured memory for operations. Bails otherwise.
# cipher-algo, s2k-cipher-algo - The algorithm used for the secret key
# digest-algo - The algorithm used to mangle the secret key
# s2k-mode 3 - Enables multiple rounds of mangling to thwart brute-force attacks
# s2k-count 65000000 - Mangles the passphrase this number of times. Takes over a second on modern hardware.
# compress-algo BZIP2- Uses a high quality compression algorithm before encryption. BZIP2 is good but not compatible with PGP proper, FYI.
encrypt() {
  gpg --symmetric -z 9 --require-secmem --cipher-algo AES256 --s2k-cipher-algo AES256 --s2k-digest-algo SHA512 --s2k-mode 3 --s2k-count 65000000 --compress-algo BZIP2 $@
}

# note: will decrypt to STDOUT by default, for security reasons. remove "-d" or pipe to file to write to disk
decrypt() {
  gpg -d $@
}