Paper 2014/257
Handycipher: a Low-tech, Randomized, Symmetric-key Cryptosystem
Bruce Kallick
Abstract
Handycipher is a low-tech, randomized, symmetric-key, stream cipher, simple enough to permit pen-and-paper encrypting and decrypting of messages, while providing a significantly high level of security by using a nondeterministic encryption procedure, multiple encryption, and randomly generated session keys.
Note: This version of the cipher has been made highly resistant to statistically based hill-climbing attacks by adding ten characters to the ciphertext alphabet, using a 41-character key instead of 31, increasing the number of null characters from five to fifteen, increasing the number of diagonals used from two to ten, and alternating the direction of encoding plaintext characters between top-down/left-right and bottom-up/right-left.
Metadata
- Available format(s)
- Category
- Secret-key cryptography
- Publication info
- Preprint.
- Keywords
- stream cipherssecret-key cryptographyrandomized homophonic substitutionhand ciphers
- Contact author(s)
- curmudgeon @ rudegnu com
- History
- 2016-02-04: last of 12 revisions
- 2014-04-20: received
- See all versions
- Short URL
- https://ia.cr/2014/257
- License
-
CC BY