This digital certificate is for Dr. Wisanu Tuntawiroon of Genia Solution in Thailand. It discusses symmetric and asymmetric encryption keys. Symmetric encryption uses a shared key for encryption and decryption, while asymmetric encryption uses a public key for encryption and a private key for decryption. Digital certificates help verify identities and provide security, confidentiality, and integrity for online messages. They normally follow the X.509 standard and can help prevent impersonation by independently verifying public keys. Signatures on documents provide legal evidence of approval and help prevent disputes.

1. D I G I T A L C E R T I F I C AT E
Dr. Wisanu Tuntawiroon
Genia Solution
(Thailand)

2. Symmetric Key

3. Symmetric Key
• An encryption system in which the sender
and receiver of a message share a single,
common key that is used to encrypt and
decrypt the message.
• Symmetric-key systems are simpler and
faster, but their main drawback is that the
two parties must somehow exchange the
key in a secure way.

4. Symmetric Key
A B C J I A I P T
C A T

5. Asymmetric Key
• Asymmetric encryption (also called
public-key encryption) involves a pair
of keys - a public and a private key.
• The public key is published in a public
directory and the corresponding private
key is kept secret.
• The sender of the data encrypts the data
with the public key of the receiver. The
data can be decrypted only with the
private key of the receiver.

6. Asymmetric Key

7. The problem with Trusting Public Key
• The imposter claims to be a certain true
person in an effort to deceive the verifier
• The imposter could sends is own public
key to the verifier
• The verifier holds will wrongly
“authenticate” the digital signature as
being that of the true person
• In other words, if a verifier does not
independently verify an applicant’s public
key

8. Digital Certificate

9. Digital Certificate
Certificate is an electronic tool equivalent to
a sealed enveloped or your signature
affixed to a document when you would like
to submit information through the network.
Certificate has a major feature in providing
security and confidentiality to a message
transmitted online. Business using
certification service can have a confidence
that they can trace the record and source
of information received.

10. Digital Certificates
• Non-repudiation. A service (proof of
origin) that allows the recipient of a
message to verify the originator of the
message.
• Confidentiality. A service that creates
confidence that a message can be read
only by those for whom it is intended.
• Integrity. A service that allows the
recipient to verify that the message has
not been altered since it left the originator.

11. X.509 Digital Certificates
Digital certificate normally follow the
ITU-T x.509 standard

12. Who can really trust on
internet?

13. Signatures and the Law
• Evidence: A signature authenticates a writing by
identifying the signer with the signed document.
• Ceremony: The act of signing a document calls to the
signer's attention the legal significance of the
signer's act, and thereby helps prevent
"inconsiderate engagements.
• Approval: In certain contexts defined by law or
custom, a signature expresses the signer's approval
or authorization of the writing, or the signer's
intention that it have legal effect.
• Efficiency and logistics: A signature on a written
document often imparts a sense of clarity and
finality to the transaction and may lessen the
subsequent need to inquire beyond the face of a
document

14. “ Thank You ”
Genia Solution (Thailand) Co., Ltd.
2339/1 , Soi Ramkhamheang 63,
Hua Mark, Ban Kapi, Bangkok 10240