[2981] in Kerberos
security book review
daemon@ATHENA.MIT.EDU (Donald T. Davis)
Wed Jan 19 22:36:17 1994
To: kerberos@MIT.EDU, krb-protocols@MIT.EDU
Cc: sbu@security.ov.com
Date: Wed, 19 Jan 1994 18:16:31 -0500
From: "Donald T. Davis" <don@security.ov.com>
here at openvision's security branch (formerly geer zolot assoc.),
we recently got a copy of bruce schneier's new book, "applied
cryptography: protocols, algorithms, and source code in c," (wiley,
'94, $44.95). we immediately ordered two more copies, because our
security jocks (me included) didn't want to share it. it is
encyclopedic, quite readable, and well-informed, and it more or less
picks up where dorothy denning's classic "cryptography and data
security" (addison-wesley, '82) left off a dozen years ago. i've
often wished lately that such a reference as schneier's existed.
schneier covers those topics in data security that touch most closely
on the encryption algorithms themselves. thus, the book doesn't
discuss authorization, audit, firewalls, or the recent formal logics
for proving protocols correct. as far as i can tell, it does cover
everything about authentication and key-distribution -- everything.
of the recent flurry of books and articles on data security that i've
seen, including some by my old colleagues from project athena, and
including a couple of others that are still in press, this one has
the clearest and most accurate treatment of kerberos.
the book is structured like a reference, but written like an undergrad
text. thus, you can enter it anywhere and make sense of what you find,
even if you don't already know the material well. it does not include
exercises or end-of-chapter summaries, but does include a bibliography
of 908 references. this makes it a good place to go, before you dive
into the literature on a topic like zero-knowledge proofs and protocols.
schneier also includes licensing and sourcing addresses for encryption
algorithms. the index, unfortunately, is a bit weak. this book would
be a bargain at twice the price.
-don davis
openvision/geer zolot associates
1 main st.
cambridge, ma 02134
contents: (my annotations abbreviate the real t.o.c.)
ch. 1: foundations
terminology, classical crypto, large numbers
part one: cryptographic protocols
ch. 2: protocol building blocks
basic crypto, one-way fcns, signatures, random numbers
ch. 3: basic protocols (includes kerberos, and correctly)
key exchange, authentication, secret splitting/sharing, etc.
ch. 4: intermediate protocols
subliminal channels, specialized signatures, bit commitment, etc.
ch. 5: advanced protocols
zero-knowledge seems to be the best-known topic here.
ch. 6: esoteric protocols
oblivious transfer, dig'l certified mail, secure elections,
dig'l cash, etc.
part two: cryptographic techniques
ch. 7: Keys
length, management, passwords, certificates
ch. 8: using algorithms
encr'n modes, multiple encr'n, hdwr vs. soft, public-key vs.
private-key, etc.
part three: cryptographic algorithms
ch. 9: mathematical background
info theory, complexity theory, number theory
ch. 10: des (& variants)
very clear exposition of internals and cryptanalysis.
ch. 11: other block algorithms
lucifer, rc2/4, skipjack, many others. schneier's favorite is
called, "idea"
ch. 12: public-key algorithms
diffie-hellman, rsa, feige-fiat-shamir, and others.
ch. 13: more public-key algorithms
elgamal, dsa, mceliece (65kbyte keys), elliptic curve crypto
(the latest rage in the literature), many others
ch. 14: one-way hash functions
md2-5, sha, & encryption-based functions.
ch. 15: random sequence generators and stream ciphers
pseudo-random & truly random numbers, their distribution & use.
ch. 16: special algorithms for protocols
detailed treatments of topics in chapters 3-6
ch. 17: example implementations
isdn, kerberos, kryptoknight, iso/x.509, pem, pgp, capstone, etc.
the kerberos discussion treats versions 5 & 4, and is clearer
than other correct treatments i've seen, and more correct than
other clear treatments.
ch. 18: politics
nsa/ncsc/nist, rsa dsi, sci.crypt, eff, cpsr, patents, export
part five: source code
vigenere, enigma, & other classics; des, idea, md5, sha, many
others. an associated pair of disks is available, which offers
this and other code, including extra des implementations, rsa,
dh, dsa, md*, ripem, tis-pem, pgp, rng's, number theory tools,
rfc's & faq's.
