Cryptography Chapter 6: Digital Signatures

A method of authenticating documents, ensuring the sender's identity and the document's integrity.

A type of cryptography based on mathematical relationships between two keys (public and private).

A secret key used to create a digital signature.

A publicly available key that can verify digital signatures.

An algorithm for creating and verifying digital signatures.

A document used to verify a public key's authenticity.

A trusted third party that issues digital certificates.

A well-known algorithm used in public-key cryptography.

Digital signatures are useful when quick action is needed.

Public key infrastructure standard that ensures safe key generation and storage.

Digital signatures are globally accepted and legally valid in many countries.

Digital signatures reduce the time spent on physical documents.

Organizations save money by going paperless, reducing resource use.

Reduced paper use lowers environmental impact.

A process that checks if a digital signature is valid using the public key and the signed data's hash.

Digital signatures provide an audit trail for record-keeping.

Creates a unique, fixed-size representation (hash) of any data, used to sign the data's condensed version.

Used for authentication and secure communication.

An algorithm (often used) for digital signature, especially when dealing with large amounts of signing data, which relies on modular exponentiation.

Algorithms that use different keys for encryption and decryption. One key is for encryption and is shared publicly, the other key for decryption must be kept secret.

Ensuring that the data has not been modified (altered or tampered with) after the sender signed it.

Verifying the sender's identity accurately

Signing a hash of the data is more efficient than signing the entire data (especially using RSA-type algorithms).

A mathematical method for verifying the authenticity and integrity of digital data using public key cryptography.

The ability to prove that a specific sender actually created a message or document, preventing them from denying their involvement.

Verifying the sender's identity by ensuring that the digital signature was created only by the individual possessing the corresponding private key.

If an attacker alters the data, the verification process at the receiver's end will fail because the hash of the modified data and the output of the verification algorithm won't match.

A private key used to create a digital signature. Only the owner of the key can use it to sign data.

A public key used to verify a digital signature. Anyone can have access to this key.

The output of a hash function. It's a unique code that represents the original data.

The combination of the original data (plaintext) and its hash digest is encrypted using the sender's private key.

Digital signatures use asymmetric cryptography, where a pair of keys (public and private) is used to secure data. The private key is used to sign, the public key is used to verify.

Digital signatures provide authenticity (verifying sender's identity), integrity (ensuring data hasn't changed), and non-repudiation (prevents the sender from denying they sent the data).

Adds a time stamp to a digital signature, proving the time of creation.

An entity that validates digital certificates and ensures the authenticity of the public key used for signing.

Signing a hash (a unique code representing the data) is more efficient than signing the entire data, especially with algorithms like RSA.

They address the issue of authentication in public key cryptography, ensuring that the message truly comes from the claimed sender and wasn't forged.

Digital signatures protect the integrity of digital data by ensuring that it hasn't been altered after signing. They also guarantee the authenticity of the sender's identity, preventing them from denying their involvement.

A hash function creates a unique fingerprint (hash) of the data. The sender then encrypts the hash using their private key to create the digital signature. The recipient uses the sender's public key to decrypt the signature and verify the hash against the data. If it matches, the signature is valid, and the data is verified.

CAs are trusted entities that verify the identity of the individuals or organizations requesting digital certificates. They also certify the public key of the sender, ensuring its authenticity. This adds an extra layer of trust to the digital signature process.

Non-repudiation is the ability to prove that a specific sender actually created a message or document. This means the sender cannot deny that they sent the message.

A digital signature uses a hash function to create a unique fingerprint of the data. If anyone changes the message, the hash won't match, proving the data has been tampered with.

Digital Signatures are crucial because they provide non-repudiation, message authentication, and data integrity. This ensures secure and trustworthy communication.

A digital signature is a method used to ensure the authenticity and integrity of a digital message or document. It uses cryptography to verify the sender's identity and ensure that the data has not been tampered with.

Digital signatures use public-key cryptography. The sender uses their private key to create the signature. The receiver uses the sender's corresponding public key to verify the signature. If the verification is successful, it proves that the message originated from the owner of the private key.

A hash function is used to create a unique, fixed-size representation (hash) of the data. This hash is then signed using the sender's private key. The receiver uses the hash to verify the integrity of the data.

The Public Key Infrastructure (PKI) standard ensures that digital keys are generated and stored securely. This helps maintain trust and security in digital signatures.

Digital signatures can be timestamped, providing evidence of the exact time the signature was created. This is useful for transactions like stock trades or legal proceedings where precise timing is crucial.

Digital signatures provide:

• Time Savings: Streamlining document signing and exchange.
• Cost Savings: Reducing paper use, printing, and storage costs.
• Environmental Benefits: Reducing paper waste and transportation costs.

Digital signatures are legally recognized in many countries. They provide a secure way to sign documents and agreements electronically, guaranteeing authenticity and non-repudiation.

Digital signatures create an audit trail that allows for tracking the history of changes made to a document. This helps maintain accountability and transparency throughout the document lifecycle.

Digital signatures are used in a wide range of applications, such as:

• Financial transactions: Securely signing financial documents and agreements.
• Legal documents: Verifying the authenticity of legal documents and contracts.
• Software distribution: Ensuring authenticity and integrity of software downloads.
• Email security: Providing authentication and non-repudiation when sending sensitive emails.

A set of rules used to create and verify digital signatures. It allows two operations: signing and verification.

It combines the data with its unique 'hash' and encrypts it using the sender's private key. The receiver uses the sender's public key to decrypt and verify authenticity and data integrity.

Digital signatures guarantee that the data hasn't been altered after signing. If any change occurs, the verification process will fail.

The receiver uses the sender's public key to verify the signature, confirming the sender's identity.

It prevents the sender from denying they sent the data. The signature proves their involvement.

It adds a timestamp to the signature, proving when the data was signed.