TLS is an IETF standard similar to SSLv3 that defines transport layer security. It uses HMAC for message authentication codes and expands secrets with a pseudo-random function based on HMAC with SHA-1 or MD5. TLS version 3.1 specifies changes to record formats, alert codes, supported ciphers, certificate types and negotiations, and cryptographic computations compared to SSLv3.

1. TLS (TRANSPORT LAYER SECURITY)

2. TLS (Transport Layer Security)
 IETF standard RFC 2246 similar to SSLv3
 with minor differences
 in record format version number
 uses HMAC for MAC
 a pseudo-random function expands secrets
 based on HMAC using SHA-1 or MD5
 has additional alert codes
 some changes in supported ciphers
 changes in certificate types & negotiations
 changes in crypto computations

3. Version Number
 The major version is 3 and the minor version is 1.

4. Message Authentication Code
 HMAC is defined as
 The MAC calculation indicated in the following
expression

5. Pseudorandom Function(PRF)

6.  PRF is defined as

7. Alert Codes
 decryption_failed
 unknown_ca
 decode_error
 protocol_version
 record_overflow( +1024 bytes)
 no_renegotiation
 user_canceled

8.  CIPHER SUITES
 Key Exchange
 Symmetric Encryption Algorithms
 CLIENT CERTIFICATE TYPES
 rsa_sign, dss_sign, rsa_fixed_dh, and
dss_fixed_dh.

9.  CERTIFICATE_VERIFY AND FINISHED MESSAGES
 CRYPTOGRAPHIC COMPUTATIONS

10. THANK YOU