What form of cryptographic service is used to establish non-repudiation?

What form of cryptographic service is used to establish non-repudiation?

• A. Symmetric Key Encryption
• B. Digital Signature
• C. Message Digest
• D. Hashing Algorithm

Answer: (B)

Non-repudiation refers to the assurance that someone cannot deny the validity of their signature on a document or the sending of a message. Digital signatures provide this level of assurance by using asymmetric cryptography, which involves a pair of keys: a private key known only to the signer and a public key available to anyone who needs to verify the signature. When a sender wants to ensure non-repudiation, they can create a digital signature by using their private key to encrypt a hash of the message. This signature, along with the original message and the sender's public key, allows others to confirm that the message was sent by the purported sender and that it has not been altered in transit. If a dispute arises, the sender cannot deny having sent the message because only their private key could have generated that specific signature, thus establishing non-repudiation. Other forms of cryptographic services mentioned do not provide the same level of non-repudiation. Symmetric key encryption relies on a shared secret key between parties, which does not establish ownership of the message or prevent denial. Message digests and hashing algorithms are used for integrity and data verification rather than for proving origin or authenticity. They do not involve the use of keys to link a

Non-repudiation refers to the assurance that someone cannot deny the validity of their signature on a document or the sending of a message. Digital signatures provide this level of assurance by using asymmetric cryptography, which involves a pair of keys: a private key known only to the signer and a public key available to anyone who needs to verify the signature.

When a sender wants to ensure non-repudiation, they can create a digital signature by using their private key to encrypt a hash of the message. This signature, along with the original message and the sender's public key, allows others to confirm that the message was sent by the purported sender and that it has not been altered in transit. If a dispute arises, the sender cannot deny having sent the message because only their private key could have generated that specific signature, thus establishing non-repudiation.

Other forms of cryptographic services mentioned do not provide the same level of non-repudiation. Symmetric key encryption relies on a shared secret key between parties, which does not establish ownership of the message or prevent denial. Message digests and hashing algorithms are used for integrity and data verification rather than for proving origin or authenticity. They do not involve the use of keys to link a