Key Managementcryptography

What is Key Management?

★Key management is the management of cryptographic keys in a cryptosystem.

★This includes dealing with the generation, exchange, storage, use, and replacement of keys.

★It includes cryptographic protocol design, key servers, user procedures, and other relevant protocols.

★It deals with entire key lifecycle.

Why are we talking about key management?

★With the rise of Cybercrime, companies are investing significant amounts in Information Security in order to protect themselves, their employees and partners, but in the end that might not be enough.

★Threats:○ compromise of confidentiality of secret keys

○ compromise of authenticity of secret or public keys.

○ unauthorized use of public or secret keys

Key management techniques

a)Symmetric-key encryption:

Key management techniques

b)Public-key

encryption:

Key LifeCycle

Distribution of Public Keys

★ Public announcement

★ Publicly available directory

★ Public-key authority ★ Public-key

certificates

Public announcement

Publicly available directory

Public-key authority

Public-key certificates

Diffie Hellman key exchange algorithm

★First public key algorithm proposed by Diffie and Hellman in

1976.

★Used only for key exchange

★Used In many commercial products

All users agree on two parameters 1) large prime number q 2) primitive root a each user (eg. A) generates their key: chooses a secret key(number): xA < q

compute their public key: yA = a^xA mod q

public keys are stored in universal directory

Algorithm:

shared session key for users A & B is KAB: KAB = axA.xB mod q = yA^xB mod q (which B can compute) = yB^xA mod q (which A can compute) KAB is used as session key in private-key encryption scheme between Alice and Bob

if Alice and Bob subsequently communicate, they will have the same key as before, unless they choose new public-keys Disadvantage: 1)man in the middle attack 2) authentication is needed

Algorithm:

Digital Certificate

Digital Certificate

★A digital identity document binding a public key to a specific

person or organization

★Certification Authorities are the digital world’s equivalent to

passport offices. They issue digital certificates and validate

holders’ identity and authority

What is the Process of obtaining a certificate?

How do You Obtain An Individual’s Public Key?

How Digital Certificates are Used for Message Encryption?

X.509 Certificates

In Chrome, Settings->Advanced Setting->Manage Certificates

In Wireshark, SSL packets captured

Thank You