WTLS (Wireless Transport Layer Security) Youngho Choung [email protected].
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WTLS WTLS (Wireless Transport Layer (Wireless Transport Layer Security) Security) Youngho Choung [email protected]
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Transcript of WTLS (Wireless Transport Layer Security) Youngho Choung [email protected].
WTLSWTLS (Wireless Transport Layer (Wireless Transport Layer
Security)Security)
Youngho [email protected]
Youngho Choung
ContentsContents
Why we need WTLS?What is WTLS?What is TLS (SSL3.0) ?WTLS FunctionsSecurity AlgorithmWTLS specificationsOther Technologies
Youngho Choung
Why we need WTLS ? (1/2)Why we need WTLS ? (1/2)
What can we do through the Cell Phone? Communication Using Internet
E-commerce On-line banking Trading Stock
Electric Cash Electric ID Watching movie, take a picture… etc…
Youngho Choung
Why we need WTLS ? (2/2)Why we need WTLS ? (2/2)
Environment problems
We need Security Solutions
Youngho Choung
What is WTLS ? (1/2)What is WTLS ? (1/2)
Youngho Choung
What is WTLS ? (1/2)What is WTLS ? (1/2)
Youngho Choung
What is TLS (SSL3.0) ? (1/3)What is TLS (SSL3.0) ? (1/3)
TLS stand for Transaction Layer SecuritySSL stand for Secure Socket Layer
Customer
웹브라우저
인터넷인터넷Internet
Shopping Mall
불안전한Unreliable Channel
암호화 구간
Youngho Choung
What is TLS (SSL3.0) ? (2/3)What is TLS (SSL3.0) ? (2/3)
Application data
Fragment
Compress
Add MAC
Encrypt
Append SSLrecord header
SSLHandshakeProtocol
SSL Change Cipher Spec
Protocol
SSL AlertProtocol HTTP
SSL Record Protocol
TCP
IP
Youngho Choung
What is TLS (SSL3.0) ? (3/3)What is TLS (SSL3.0) ? (3/3)
Handshake protocolHandshake protocol
Key establishment algorithmDiffie -Hellman , RSA, Fortezza
Certificate RSA, DSS, Fortezza
Record protocolRecord protocol
MAC algorithmMD5, SHA-1
Encryption algorithmRC2, RC4, DES, Triple DES, IDEA,Fortezza
Youngho Choung
WTLS FunctionsWTLS Functions
Data IntegrityPrivacyAuthenticationDoS (Denial of Service) protectionOptional
Youngho Choung
Security AlgorithmSecurity AlgorithmHash FunctionHash Function
Dyejsmldmnf
mdfnmd , sdd
fnfnfnlkfekkfe
ekfkjefjefelfee
----------------
Any Length Plain Text
Hash Function
Fix length Encrypted Text
MD5, MD4, Hash, SHA-1, etc
Youngho Choung
Security AlgorithmSecurity AlgorithmBlock CipherBlock Cipher
(1) Diagram
M E C(Message) (Ciphertext)
K(Key)
M , C , K : n bit blocksExamples ( in bits)
{128,192,256}{128,192,256}{128,192,256}AES646464DESKCM
Youngho Choung
Security AlgorithmSecurity AlgorithmBlock CipherBlock Cipher
(2) Encryption : Combination of Substitution &
Permutation
Decryption : Inverse of Encryption
(3) Classical ciphers
a. Permutation Ciphers
b. Substitution Cipher : Caesar Cipher
Youngho Choung
Security AlgorithmSecurity AlgorithmPublic KeyPublic Key
Key distribution is difficult Tow Communicants already share a key or have
the use of a key distribution center
Characteristic (public) encryption key ≠ (private) decryption
key
Youngho Choung
Security AlgorithmSecurity AlgorithmPublic KeyPublic Key
Bob'sprivate key
Bob'spublic key
Transmittedciphertext
Encryption Algorithm
Plaintextinput
Joy Ted
Decryption Algorithm
Plaintext output
Alice'spublic key ring
Youngho Choung
WTLS Specifications (1/5)WTLS Specifications (1/5)
Handshaking protocol Full handshaking protocol Abbreviated handshaking protocol Optimized handshaking protocol
Alert protocolChange Cipher spec protocolRecord protocol
Youngho Choung
WTLS SpecificationsWTLS Specifications
Full handshaking
Youngho Choung
WTLS SpecificationsWTLS Specifications
Abbreviated handshaking
Youngho Choung
WTLS SpecificationsWTLS Specifications
Optimized full handshaking
[ChangCipherSpec]FinishedApplication Data
ServerHelloCertificate[ChangeCipherSpec]Finished
Youngho Choung
WTLS Specifications (4/5)WTLS Specifications (4/5)
Alert protocol
Change Cipher spec protocol
Youngho Choung
WTLS Specifications (5/5)WTLS Specifications (5/5)
Record Protocol
Youngho Choung
Let’s talk about……later..Let’s talk about……later..
WALS(Wireless Application Layer Security)WPKI(Wireless Public-Key Infrastructure)WIM(WAP Identity Module References
