Precise implementation of **Web Crypto API** and **AES-GCM** 256-bit encryption in modern cryptographic infrastructure
The next-generation browser standard Web Crypto API is directly integrated into the heart of this system, and through this, encryption is performed using the AES-GCM method, which boasts the highest level of confidentiality.
AES is an abbreviation for Advanced Encryption Standard, and is a block cipher algorithm that has been adopted as the current US government standard.
This design uses a maximum key length of 256 bits to create a defense layer that requires astronomical calculation time against brute force attacks.
GCM, or Galois/Counter Mode, is a form of authenticated encryption that authenticates data at the same time as encryption, and has the characteristics of high-speed parallel processing using counter mode and simultaneous processing of message authentication code generation using Galois field multiplication.
This design ensures the confidentiality and integrity of plaintext at the same time, creating a robust data protection space in the client environment that goes beyond simple data obfuscation.
By utilizing a native API that does not depend on the operating system or external libraries, processing overhead is minimized and encryption processing is achieved with extremely low latency.
Irreversible reinforcement using iterative processing of key derivation function PBKDF2 and cryptographic pseudorandom salt
The Password-Based Key Derivation Function 2 or PBKDF2 algorithm is used as a mechanism to generate strong cryptographic keys from human-memorable passwords.
The entered password is not used directly as an encryption key, but is combined with a high-entropy salt value generated by the cryptographic pseudo-random number generator Crypto.getRandomValues function.
This combined data is forced to undergo an iteration process that uses the hash function SHA-256 exactly 100,000 times. This number of iterations of 100,000 times was designed to intentionally increase the computational cost for dictionary attacks and rainbow table attacks using modern graphics boards and application-specific integrated circuits.
The salt value is completely newly generated each time ciphertext is generated, so even if you input the same password and the same plaintext, the ciphertext output will be a completely different byte string each time.
This makes reverse engineering attempts to calculate the original password from a specific ciphertext extremely difficult both theoretically and physically.
Data tampering detection system using authentication tags and strict verification logic for complex processes
The most important part of the decryption process is the authentication phase, which verifies that the input ciphertext has not been intentionally tampered with by a third party or that no bits have been lost on the communication path.
The AES-GCM algorithm automatically generates a 128-bit authentication tag at the final stage of the encryption process and adds it to the end of the ciphertext.
When decryption is requested, the system first derives the decryption key again using PBKDF2 from the input password and recalculates the authentication tag using the initialization vector IV provided with the ciphertext.
If the calculated tag and the tag given to the ciphertext do not match even by one bit, the decryption algorithm immediately throws an exception and terminates the process.
This completely negates attempts by malicious attackers to extract fraudulent plaintext by modifying part of the ciphertext, as well as cryptanalysis techniques such as padding oracle attacks.
A strict zero-trust verification model has been established in which decrypted plaintext is expanded into memory and output to the screen only when data integrity is proven.
Proof of client-side fully local processing based on zero-knowledge architecture
To ensure the confidentiality of information both physically and logically, the system is designed as a completely standalone client-side application with no communication to external servers.
All data of the input plaintext password, generated encryption key salt value initialization vector, and ciphertext are processed only in the browser's volatile memory and are not sent to an external database or analysis API.
It is technically possible to prove that plaintext data and encryption key information has not leaked outside by monitoring the network tab or capturing packets using a proxy tool.
With this zero-knowledge architecture, even the provider has no way of knowing what information the user has encrypted, completely eliminating the risk of data leaks due to server hacking or internal crimes.
The design allows all functions to operate without delay even in an offline environment where the Internet connection is completely cut off, making it the embodiment of the ultimate self-contained security model.
Real-time stream processing and seamless conversion mechanism between Base64 and hexadecimal representation
The user interface layer implements real-time encryption and decryption stream processing triggered by input field keystroke events.
The input string is immediately encoded into a UTF-8 byte array and fed into the Web Crypto API's asynchronous processing pipeline.
The generated binary ciphertext is instantly converted to Base64 encoding or Hex, making it human readable and safe to copy and paste.
Base64 representation is suitable for keeping data size compact, and Hex representation is suitable for embedding in programming language source code or specific configuration files.
These representation formats can be switched instantly using a toggle switch on the interface, and the delay in the conversion process is limited to milliseconds.
Furthermore, the ciphertext generated through native collaboration with the clipboard API is safely transferred to the operating system's clipboard with a single click, preventing copy omissions due to human error.
Best Practices for Protecting Confidential Memos and Managing the Secure Information Lifecycle
By integrating this encryption mechanism into business and personal information management, it becomes possible to utilize cloud storage and public text sharing services as secure repositories of confidential information.
For example, we recommend using this system to encrypt highly confidential text data, such as recovery phrases and source code fragments of financial institution PIN numbers, and then saving the Base64 strings in a general memo app.
In this case, even if the company operating the memo app were to suffer a data breach, only a series of undecipherable ciphers would be leaked.
It acts as the ultimate cold storage as key passwords are physically stored only in the user's brain. When using the information, by entering the ciphertext and password into this system again, the plaintext is temporarily expanded into volatile memory, and after completing the work, all traces can be completely erased by closing the browser tab.
Such information lifecycle management is one of the strongest defense tactics for individuals to maintain complete control over their information in today's digital society.