Reference
PKI
“PKI” refers to the overall technology
and product infrastructure for using
public key cryptography. It encompasses technologies for public key cryptography such as RSA, browsers that incorporate SSL, e-mail encrypted using
a standard such as S/MIME, and servers of certification authorities that issue
digital certificates. It was proposed as a
solution to enable the secure execution
of electronic commerce.
Abbreviation for “Public Key Infrastructure.”
Reference
RSA
“RSA” is a method for public key cryptography that was developed with a focus on the challenge of factoring large
numbers into its prime components.
(2)Public key cryptography
“Public key cryptography” is an approach that uses different keys (secret
key and public key) for encryption and decryption. The secret key is for
personal use and must not be shared with a third party. The public key is
widely published to third parties, and is registered with a certification authority for publication.
“RSA” is s method that is typically used for public key cryptography.
The framework and characteristics of communications using public key
cryptography are summarized below.
The recipient generates a secret key and public key, and registers the
public key to the public key list of a certification authority. The recipient
then receives a certificate.
The sender takes the recipient’s public key from the public key list of the
certification authority.
The sender sends the ciphertext encrypted with the recipient’s public key.
Reference
CA
A “CA” is an entity that issues certificates that attest to the validity of a public key used for purposes such as public
key cryptography or digital signatures.
Abbreviation for “Certification Authority.”
The recipient uses their own secret key to decrypt the ciphertext.
●Characteristics
• Uses a public key which is suited for communications with many recipients.
• Easy to manage keys.
• Slow encryption and decryption speed.
Sender
Recipient
Transmit
Encryption
Plaintext
Decryption
Ciphertext
Ciphertext
Secret key
Public key
Certification
authority
Public key of
recipient
299
Plaintext
Ciphertext
Pair of keys