The post-quantum cryptography tool.
This is a GnuPG-like unix program for encryption and signing that uses only quantum-computer-resistant algorithms:
McEliece cryptosystem (compact quasi-dyadic variant) for encryption
Hash-based Merkle tree algorithm (FMTSeq variant) for digital signatures

Why this?
Go read

package downloads:

There is a complete, UNIXy manual page supplied with the package. You can view it online here:

Quick How-To
Everything is meant to work mostly like GnuPG, but with some good simplicity margin. Let's play with random data!

ccr -g help
ccr -g fmtseq128-sha --name "John Doe"    # your signature key
ccr -g mceqd128 --name "John Doe"     # your encryption key

ccr -K  #watch the generated keys
ccr -k

ccr -p -a -o my_pubkeys.asc -F Doe  # export your pubkeys for friends

#see what people sent us
ccr -ina < friends_pubkeys.asc

#import Frank's key and rename it
ccr -ia -R friends_pubkeys.asc --name "Friendly Frank"

#send a nice message to Frank (you can also specify him by @12345 keyid)
ccr -se -r Frank < Document.doc > Message_to_frank.ccr

#receive a reply
ccr -dv -o Decrypted_verified_reply.doc <Reply_from_frank.ccr

#rename other's keys
ccr -m Frank -N "Unfriendly Frank"

#and delete pukeys of everyone who's Unfriendly
ccr -x Unfri

#create hashfile from a large file
ccr -sS hashfile.ccr < big_data.iso

#verify the hashfile
ccr -vS hashfile.ccr < the_same_big_data.iso

Option reference
For completeness I add listing of all options here (also available from ccr --help)
Usage: ./ccr [options]

Common options:
 -h, --help     display this help
 -V, --version  display version information
 -T, --test     perform (probably nonexistent) testing/debugging stuff

Global options:
 -R, --in      input file, default is stdin
 -o, --out     output file, default is stdout
 -a, --armor   use ascii-armored I/O
 -y, --yes     assume that answer is `yes' everytime

 -s, --sign     sign a message
 -v, --verify   verify a signed message
 -e, --encrypt  encrypt a message
 -d, --decrypt  decrypt an encrypted message

Action options:
 -r, --recipient    encrypt for given user
 -u, --user         use specified secret key
 -C, --clearsign    work with cleartext signatures
 -b, --detach-sign  specify file with detached signature
 -S, --symmetric    enable symmetric mode of operation where encryption
            is done using symmetric cipher and signatures are
            hashes, and specify a filename of symmetric key or hashes

Key management:
 -g, --gen-key        generate specified keypair, `help' lists algorithms
 -k, --list           list keys
 -K, --list-secret
 -i, --import         import keys
 -I, --import-secret
 -p, --export         export keys
 -P, --export-secret
 -x, --delete         delete matching keys
 -X, --delete-secret
 -m, --rename         rename matching keys
 -M, --rename-secret

Key management options:
 -n, --no-action    on import, only show what would be imported
 -N, --name         specify a new name for renaming or importing
 -F, --filter       only work with keys with matching names
 -f, --fingerprint  format full key IDs nicely for human eyes