Cisco Cyber Security Practice Exam

What algorithm is used by governments to create digital signatures, which utilizes large number factorization?

1. RSA

2. DSA

3. SHA

4. ECC

The correct answer is: DSA

The algorithm used by governments for creating digital signatures that relies on large number factorization is RSA (Rivest–Shamir–Adleman). RSA is a widely used public-key cryptosystem that generates keys based on the difficulty of factoring the product of two large prime numbers. The security of RSA is fundamentally linked to the challenge presented by this mathematical problem, making it one of the first public-key algorithms and a standard for secure data transmission. Digital signatures created using RSA involve the signing process, where a hash of the message is created and then encrypted with the private RSA key, generating a signature that can be verified with the corresponding public RSA key. This method establishes authenticity and non-repudiation, ensuring that a digitally signed document truly comes from the stated sender. In contrast, DSA (Digital Signature Algorithm) also provides a means of signature generation but it relies on different mathematical foundations, specifically discrete logarithm problems, rather than on large number factorization. SHA (Secure Hash Algorithm) is primarily a hash function used to ensure data integrity but does not involve key pairs. ECC (Elliptic Curve Cryptography) provides digital signatures through different mathematical principles involving elliptic curves and offers shorter keys for the same level of security compared to RSA