Cryptography is the practice of secure communication techniques that protect information from unauthorized access, ensuring confidentiality, integrity, and authenticity through algorithms and keys. It encompasses symmetric and asymmetric cryptography, hash functions, and applications like secure communication, data encryption, and digital signatures. Key management and advancements such as quantum cryptography are critical for evolving security measures in digital systems.

2. In your own
understandin
g
what is
cryptography
?
Cryptography is the study
and practice of secure
communication techniques
used to protect information
from unauthorized access or
alteration. It involves the use
of mathematical algorithms
and keys to convert plaintext
data into ciphertext (encoded
data) and vice versa. The
primary goals of
cryptography are the
following:
confidentiality, integrity, and
authenticity:

3. CONFIDENTIALITY
Cryptography
ensures that only
authorized parties
can access and
understand the
data. It prevents
eavesdroppers
from deciphering
the encrypted
information.

4. Integrity
Cryptography helps
verify that the data
has not been
tampered with during
transmission or storage.
If any unauthorized
changes are made to
the ciphertext, it
should become
evident.

5. Authenticity
Cryptography can
be used to confirm
the identity of the
parties involved in a
communication.
Digital signatures, for
example, are a
cryptographic
technique used to
verify the
authenticity of a
message sender.

6. Cryptography relies on
various cryptographic
algorithms, including
symmetric-key cryptography
(where the same key is used
for both encryption and
decryption) and
asymmetric-key
cryptography (which uses a
pair of public and private
keys).
It plays a crucial role in
ensuring the security and
privacy of information in
digital systems, such as
secure communication
over the internet, data
encryption, and digital
signatures for
authentication.

7. Cryptography is a vast
and complex field with
a rich history and
numerous applications.
Here are some key
aspects and concepts in
cryptography:
1. Types of Cryptography:
Symmetric-Key Cryptography
Asymmetric-Key Cryptography
Hash Functions

8. Symmetric-Key Cryptography:
In symmetric-key cryptography, the
same key is used for both encryption
and decryption. It's efficient but
requires secure key distribution.
Asymmetric-Key Cryptography:
Asymmetric cryptography, also
known as public-key cryptography,
uses a pair of keys: a public key for
encryption and a private key for
decryption. This is often used for
secure key exchange and digital
signatures.
Hash Functions:
Cryptographic hash functions take
input data and produce a fixed-size
string of characters, which is typically
a hexadecimal number. They are used
for data integrity verification

9. 2. Applications:
Data Encryption
Secure Communication
Digital Signatures
Secure File Storage
Secure Communication: Cryptography is
used to secure communication over the
internet. Protocols like HTTPS (used for
secure web browsing) rely on encryption
to protect data during transmission.
Data Encryption: Cryptography is used to
encrypt sensitive data, such as
passwords, credit card numbers, and
personal messages, to keep it
confidential.
Digital Signatures: Digital signatures
provide a way to verify the authenticity
and integrity of electronic documents.
They are often used in financial
transactions and document
authentication.
Secure File Storage: Encryption is used
to secure data at rest, such as files
stored on a computer or in the cloud

10. 3. Key Management:
Proper key management is crucial in
cryptography. It involves generating,
storing, and distributing keys securely to
authorized parties while protecting them
from unauthorized access
4. Cryptanalysis:
Cryptanalysis is the study of analyzing
and breaking cryptographic systems.
Cryptanalysts use various techniques to
attempt to decrypt encrypted data
without knowing the key.
5. Quantum Cryptography:
Quantum cryptography is a field that
explores the use of quantum mechanics
to secure communication. It offers the
potential for ultra-secure encryption
methods, but it is still in the experimental
stage.

11. Cryptography is a
constantly evolving
field, with new
challenges and
techniques emerging
as technology
advances.
It plays a vital role in
securing digital
communication,
protecting sensitive
information, and
ensuring the integrity
of data in our
increasingly connected
world.

12. Here are some specific examples
of cryptography and its
applications:
Secure Email Communication:
Online Banking Transactions:
Password Storage
Blockchain Technology:
Virtual Private Networks (VPNs):
Smartphone Biometric Authentication:
Two-Factor Authentication (2FA):

13. Secure Email Communication:
•Example: When you send an
email via a secure email service or
use end-to-end encryption, your
message and attachments are
encrypted using cryptographic
algorithms.
•How it works: Public-key
cryptography is often used here.
The recipient's public key is used
to encrypt the message, and only
the recipient's private key can
decrypt it.
Online Banking Transactions:
•Example: When you log in to
your online banking account or
make a financial transaction,
cryptography is at work to
protect your data.
•How it works: Secure
communication protocols like
HTTPS ensure that your data is
encrypted during transmission.
Also, digital signatures may be
used to verify the authenticity of
banking transactions

14. Password Storage:
•Example: When you create an
account on a website, your
password is not stored in plain text
but is hashed and salted before
storage.
•How it works: Cryptographic hash
functions, such as SHA-256, are
used to irreversibly convert your
password into a unique hash value.
Salting adds additional security by
appending a random value to the
password before hashing.
Blockchain Technology:
•Example: Cryptocurrencies like
Bitcoin rely on blockchain
technology, which uses
cryptography to secure
transactions and ensure the
integrity of the blockchain.
•How it works: Transactions are
digitally signed using the sender's
private key and can only be
verified with the sender's public key.
Blocks in the blockchain are
secured using cryptographic
hashes.

15. Virtual Private Networks (VPNs):
•Example: When you use a VPN to
browse the internet securely and
privately, cryptography is used to
create a secure tunnel for your
data.
•How it works: VPNs use encryption
to protect data as it travels
between your device and the VPN
server, preventing eavesdroppers
from intercepting your traffic.
Smartphone Biometric
Authentication:
•Example: Many modern
smartphones use biometric data
like fingerprints or facial
recognition to unlock the device
securely.
•How it works: Biometric data is
stored in a highly secure,
encrypted form on the device.
When you provide your
fingerprint or face, the device
uses cryptographic processes to
verify your identity.

16. Two-Factor Authentication (2FA):
•Example: When you enable 2FA
for your accounts, you often
receive a one-time code via SMS
or a dedicated authentication
app.
•How it works: These codes are
generated using cryptographic
algorithms and are time-based or
linked to a specific device, adding
an extra layer of security to your
accounts.
These are just a few
examples of how
cryptography is used in
various aspects of our
digital lives to protect
data, secure
transactions, and ensure
privacy and security.

17. "Crypto" and
"cryptography" are
related terms, but
they have slightly
different meanings
and contexts:
Cryptography:
•Definition: Cryptography is the
science and practice of secure
communication techniques used to
protect information from unauthorized
access or alteration. It encompasses
the principles, techniques, and
mathematical algorithms used to
ensure the confidentiality, integrity,
and authenticity of data.
•Usage: Cryptography is a broader
term that refers to the field as a whole
and the theoretical and practical
aspects of securing information
through encryption, decryption, digital
signatures, and more.

18. Crypto:
•Definition: "Crypto" is an informal
abbreviation or shorthand for
"cryptocurrency." Cryptocurrencies
are digital or virtual currencies that
use cryptography for security and
operate independently of a central
authority, such as a government or
bank.
•Usage: "Crypto" is often used to
refer specifically to the world of
cryptocurrencies like Bitcoin,
Ethereum, and others. It's used to
discuss topics related to digital
currencies, blockchain technology,
and decentralized finance (DeFi)
In summary, "cryptography" is
the broader field concerned
with secure communication
techniques and the underlying
principles and mathematics,
while "crypto" is often used as
a shortened form to refer to the
specific context of
cryptocurrencies and related
technologies.The usage of
these terms can vary depending
on the context of the
conversation.

20. GROUP MEMBER
April Jean Torres
Earyen Faburada
Kim Lawanan
Winmar Faburada