#21unit 1technology solutions
Public key encryption using Hash digest
Combining hashes with public key cryptography.
Verifying a stock order with a digital signature
Alice sends Bob a signed instruction 'Buy Cisco @ $16.' She hashes the message, encrypts the hash and message with Bob's public key, then encrypts the result with her private key — creating a digital signature. Bob uses Alice's public key to authenticate, his private key to decrypt, and re-hashes the message to confirm it was not altered.
DocuSign, Adobe eSign, and Sertifi offer online digital signature solutions, and many insurance and finance companies allow customers to electronically sign documents.