Final answer:
MD5 is a cryptographic hash function that produces a 128-bit hash value, which is expressed as a 32-digit hexadecimal number and is used to check data integrity. However, it is not suitable for SSL certificates and digital signatures due to security vulnerabilities.
Step-by-step explanation:
MD5 (Message Digest Algorithm 5) is a widely used cryptographic hash function that produces a 128-bit hash value. This is typically expressed as a 32-digit hexadecimal number.
Option 1 is true: MD5 produces a 128-bit hash value whereas SHA-1 (Secure Hash Algorithm 1) produces a 160-bit hash value.
Option 2 is true: MD5 is used to check the data integrity of files. By comparing the MD5 hash of a file to a previously calculated hash, one can determine whether the file has been altered or corrupted.
Option 3 is true: MD5 hash values are commonly represented as a 32-digit hexadecimal number.
Option 4 is false: MD5 is not considered secure for SSL certificates or digital signatures anymore due to vulnerabilities that can lead to collision attacks, where two different inputs produce the same hash value. More secure algorithms like SHA-256 are now recommended for these purposes.