Group Theoretic Cryptography

PRELIMINARIES

Mathematical background
Algebraic structures in a nutshell
Finite groups
Summary and further reading
Exercises

Basics on complexity
Complexity classes
Asymptotic notation and examples
Summary and further reading
Exercises

Cryptology: An introduction
A short historical overview
     Historical encryption schemes
     Public-key cryptography
Modern cryptology
Summary and further reading
Exercises

PUBLIC-KEY ENCRYPTION

Provable security guarantees
Public-key encryption revisited
Characterizing secure public-key encryption
One-way functions and random oracles
The general Bellare-Rogaway construction
IND-CCA security with an Abelian group: RSA-OAEP
One-way functions from non-Abelian groups?
Summary and further reading
Exercises

Public-key encryption in the standard model
The Crame-Shoup encryption scheme from 1998
Going beyond: Tools
     Projective hash families
     Subset membership problems
     Hash proof systems
General Cramer-Shoup encryption scheme
A concrete instantiation
Projective hash families from (non-Abelian) groups
     Group action systems
     Group action projective hash families
Summary and further reading
Exercises

Public-key encryption using infinite groups
The word problem in finitely presented groups
     The encryption scheme of Wagner and Magyarik
     Polly Cracker
     A successor of the Wagner-Magyarik scheme
Using a group that is not finitely presentable?
Braid groups in cryptography
     Basics on braid groups
     Some computational problems in the braid group Bn
Summary and further reading
Exercises

III SECRET-KEY ENCRYPTION

Block ciphers
Advanced Encryption Standard
     Specifying the round function
     Key schedule
      Encryption and decryption with AES
Data Encryption Standard
     General structure of DES: A Feistel cipher
     Round function of DES
     Key schedule
Permutation Group Mappings
Modes of operation
     Electronic codebook (ECB) mode
     Cipher block chaining (CBC) mode
     Cipher feedback (CFB) mode
     Output feedback (OFB) mode
     Counter (CTR) mode
Summary and further reading
Exercises

Cryptographic hash functions and message authentication codes
Cryptographic hash functions
Deriving a hash function from a block cipher
Cayley hash functions
Message authentication codes
     Keyed-Hash Message Authentication Code
     Cipher-based Message Authentication Code
Summary and further reading
Exercises

OTHER CRYPTOGRAPHIC CONSTRUCTIONS

Key establishment protocols
Setting the stage
     Provable security for key exchange protocols
     A secure construction
Anshel-Anshel-Goldfeld key exchange
Braid-based key exchange
Constructions over matrix groups
Summary and further reading
Exercises

Signature and identification schemes
Definitions and terminology
RSA signatures: FDH and PSS
Identification schemes
Summary and further reading
Exercises

APPENDIX

Solutions to selected exercises
Solutions to selected exercises of Part I
Solutions to selected exercises of Part II
Solutions to selected exercises of Part III
Solutions to selected exercises of Part IV

References
Index

Biography

Maria Isabel Gonzalez Vasco, Rainer Steinwandt

"Group Theoretic Cryptography is highly welcome. It provides an excellent introduction in group-based cryptography where algebraic properties of the platform groups, mainly from combinatorial group theory, are used prominently in both devising cryptosystems and in cryptanalysis. In particular the difficulty, in a complexity sense, of certain algorithmic problems in finitely presented groups has been crucial in encryption and decryption. ... I highly recommend the book under review. It is of great value for researchers in the area as well as for advanced students which start to work in cryptology. The excellent figures and algorithmic descriptions are clear and good to understand. They help the readers to see the important points.
—Gerhard Rosenberger (Hamburg), writing in Zentralblatt MATH 1321 – 1