cryptography: state of the science asiacrypt 2003 invited talk
DESCRIPTION
CRYPTOGRAPHY: STATE OF THE SCIENCE ASIACRYPT 2003 invited talk. Adi Shamir Computer Science Dept The Weizmann Institute Israel. Cryptography: major trends. Cryptography: major trends. From secret to public. Cryptography is central. Com&info theory. Comp science. crypto. Math& stat. - PowerPoint PPT PresentationTRANSCRIPT
CRYPTOGRAPHY:STATE OF THE SCIENCE
ASIACRYPT 2003 invited talk
Adi ShamirComputer Science DeptThe Weizmann Institute
Israel
Cryptography: major trends
Cryptography: major trends
From secret to public
Cryptography is central
cryptoMath&
statComputersand chips
Com&infotheory
Compscience
Hi-techindustry
Policyissues
Cryptography is fun Gets lots of media attention Attracts hackers Is full of delightful ideas Serves as an excellent educational tool
Cryptography: major trends
From secret to public
From national to international
The geography of cryptography
Publicly started in the US
The geography of cryptography
Publicly started in the US
Followed by Europe
The geography of cryptography
Publicly started in the US
Followed by Europe
Is rapidly expanding in Asia
Cryptography: major trends
From secret to public
From national to international
From art to science
Cryptography as a scientific discipline
Is thriving as a scientific area of research:
Taught at most major universities Attracts many excellent students Discussed at many conferences
(>25 in the next 6 months!) Published in hundreds of papers (e.g., EPRINT) Major conferences have >500 attendees
(Major trade shows have >10,000 attendees)
Received the ultimate seal of approval from the general CS community (the Turing award…)
Should we rename the field?
Cryptography means “secret writing”
The official naming of the field:Cryptology = Cryptography +
cryptanalysis
Should we rename the field?
Cryptography means “secret writing”
The official naming of the field:Cryptology = Cryptography + cryptanalysis
These terms have problematic conotations
Many research subfields do not deal with the encryption or decryption of secret information
Should we rename the field?
Cryptography means “secret writing”
The official naming of the field:Cryptology = Cryptography +
cryptanalysis
These terms have problematic conotations
Many research subfields do not deal with the encryption or decryption of secret information
I propose to call the broader field Adversity Theory = cryptology + other
areas
Cryptography: major trends
From secret to public
From national to international
From art to science
From math to physics
Related scientific fields: OLD COMBINATIONS: Probability and statistics Algebra Number Theory
Related scientific fields: OLD COMBINATIONS: Probability and statistics Algebra Number Theory
NEW COMBINATIONS: Signal processing (in steg, fingerprinting) Electronics (in side channel attacks) Physics (in quantum computers and
crypto)
Cryptography: major trends
From secret to public
From national to international
From art to science
From math to physics
From theory to practice
Cryptography unites Theory &
practice Practical theory: - using abstract math tools in cryptanalysis - proving the security of real protocols -developing new cryptographic schemes
Theoretical practice: - developing new notions of security, complexity,
logics, and randomness - turning cryptography from art to science
New challenges in cryptography
Payment systems Cellular telephony Wi-Fi networks RFID tags DRM systems
Cryptography: major trends
From secret to public
From national to international
From art to science
From math to physics
From theory to practice
From political to legal issues
Cryptographic misconceptions
By policy makers: crypto is dangerous, but: - weak crypto is not a solution - controls can’t stop the inevitable
By researchers: A provably secure system is secure, but: - proven false by indirect attacks - can be based on false assumptions - requires careful choice of parameters
By implementers: Cryptography solves everything, but: - only basic ideas are successfully deployed - only simple attacks are avoided - bad crypto can provide a false sense of security
The three laws of security:
Absolutely secure systems do not exist
To halve your vulnerability, you have to double your expenditure
Cryptography is typically bypassed, not penetrated
Cryptography: A rapidly moving field
Cryptography: A rapidly moving field
75-80: Public key cryptography, basic schemes
Cryptography: A rapidly moving field
75-80: Public key cryptography, basic schemes
80-85: Theoretical foundations, new protocols
Cryptography: A rapidly moving field
75-80: Public key cryptography, basic schemes
80-85: Theoretical foundations, new protocols
85-90: Zero Knowledge, secure computation
Cryptography: A rapidly moving field
75-80: Public key cryptography, basic schemes
80-85: Theoretical foundations, new protocols
85-90: Zero Knowledge, secure computation
90-95: Diff&lin cryptanalysis, quantum comp
Cryptography: A rapidly moving field
75-80: Public key cryptography, basic schemes
80-85: Theoretical foundations, new protocols
85-90: Zero Knowledge, secure computation
90-95: Diff&lin cryptanalysis, quantum comp
95-00: Side channel attacks, elliptic curves
Cryptography: A rapidly moving field
75-80: Public key cryptography, basic schemes
80-85: Theoretical foundations, new protocols
85-90: Zero Knowledge, secure computation
90-95: Diff&lin cryptanalysis, quantum comp
95-00: Side channel attacks, elliptic curves
00-05: ???
The basic schemes: Major trends
The basic schemes: Major trends
Secret key cryptography: DES out, AES in
The basic schemes: Major trends
Secret key cryptography: DES out, AES in
Public key cryptography: RSA steady, EC improving, faster schemes increasingly risky and less appealing. Should not be used for long term security.
The basic schemes: Major trends
Secret key cryptography: DES out, AES in
Public key cryptography: RSA steady, EC improving, faster schemes increasingly risky and less appealing. Should not be used for long term security.
Quantum schemes: the wild card
Some of my controvertial positions:
Some of my controvertial positions:
When applied in practice:
Some of my controvertial positions:
When applied in practice:
Security should not be overdone
Some of my controvertial positions:
When applied in practice:
Security should not be overdone
Security should not be overexposed
Some of my controvertial positions:
When applied in practice:
Security should not be overdone
Security should not be overexposed
Security should not be underregulated
Some of my controvertial positions:
When applied in practice:
Security should not be overdone
Security should not be overexposed
Security should not be underregulated
Security should be guided by an ethical code
Some of my controvertial positions:
When applied in practice:
Security should not be overdone
Security should not be overexposed
Security should not be underregulated
Security should be guided by an ethical code
Security should be complemented by legal measures
Cryptographic status report
In each of the six major subareas I’ll summarize:
The major achievements so far Strong and weak points, major
challenges A 1-10 grade
Theory of cryptography Well defined primitives & definitions of security Well understood relationships between notions Deep connections with randomness &
complexity Beautiful mathematical results
Highly developed theory Excellent design tools Challenge: reduce dependence on assumptions
Final grade: 9
Public key encryption and signature schemes
RSA, DH, DSA Based on modular arithmetic, EC, other ideas(?)
Vigorous cryptanalytic research Excellent theory Expanding applications Challenges: Break a major scheme, make a new
one
Final grade: 8
Secret key cryptography – block ciphers
DES, AES, modes of operation Differential and linear cryptanalysis
Good cryptanalytic tools Reasonable choice of primitives Many good schemes Challenge: Connect strong theory with strong
practice
Final grade: 7
Secret key cryptography – stream ciphers
Linear feedback shift registers Fast correlation attacks, algebraic attacks
Limited cryptanalytic tools Narrow choice of primitives Many insecure schemes Challenge: Improve weak theory and weak
practice
Final grade: 4
Theoretical Cryptographic protocols
Zero knowledge interactive proofs Secure multiparty computations Almost anything is doable and provable
Many gems Theoretical protocols are too slow Challenge: Make the strong theory practical
Final grade: 8
Practical Cryptographic protocols
Many ad-hoc ideas Proofs in the random oracle model (ROM) Rapidly expanding body of results
Lots of buggy protocols Reasonable design primitives Improving theory Challenges: incorporate side channel attacks,
ROM
Final grade: 5
Cryptographic predictions: AES will remain secure for the forseeable
future Some PK schemes and key sizes will be
successfully attacked in the next few years Crypto will be invisibly everywhere Vulnerabilities will be visibly everywhere Crypto research will remain vigorous, but
only its simplest ideas will become practically useful
Non-crypto security will remain a mess
Summary It was a thrilling 25 year journey
The best is yet to come
Thanks to everyone!