1 Information Security Practice I Lab 5

2 Cryptography and security Cryptography is the science of using mathematics to encrypt and decrypt data. Cryptography enables you to store sensitive information or transmit it across insecure networks (like the Internet) so that it cannot be read by anyone except the intended recipient.

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4 Keys Keys are used for encryption and decryption. There are two methods of doing this: symmetrical scheme and asymmetrical scheme: Symmetrical scheme uses the same key for encryption and decryption while in asymmetrical scheme, a public key is used for encryption and a private key used for decryption. Symmetrical scheme has the problem of key distribution but usually works faster. The public key in asymmetrical scheme is made public and can be accessed by anyone. But a message encrypted using the public key can only be viewed by using the private key of the key pair. So asymmetrical scheme is safer and usually works slower. The asymmetrical scheme is often called public key cryptography

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7 PGP Pretty Good Privacy is software that consists of tools to encrypt, decrypt, and digitally sign computer data and .

8 PGP It performs the following functions to allow you to sign and encrypt Create keys. PGP creates your key pair, your public key and private key. Manage keys. PGP allows you to store other users’ public keys on a local key ring. Encrypt/decrypt . Colleagues use your public key to encrypt messages to you. You use your private key to decrypt them. Sign/authenticate . You use your private key to digitally sign messages to your colleagues. Your colleagues use your pubic key to decrypt your signature and verify the message actually come to you.

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