Caesar cipher program in java
Caesar cipher program in java. The Caesar Cipher technique is one of the earliest and simplest methods of encryption technique. import java. Take below example. Salah satu teknik dasar yang umum dipelajari dalam enkripsi ialah Caesar Cipher. Step 3: Creating a new java class. Please help me! Step-1: Get each character from the secret message by using the toCharAt () method of the Java String class. 76 KB. it is z (the last char of your String), then you take alphabet. Monoalphabetic Cipher : A monoalphabetic cipher is any cipher in which the letters of the plain text are mapped to cipher text letters based on a single alphabetic key. For example, if key is 3 then we have to replace the character by another character that is 3 positions down to it. Shift letters by a certain number of characters. Question: JAVA program Caesar Cipher Please complete decryption section (match encryption section). Key: 7 7 7 7. Now let’s see an example of symmetric encryption and decryption. It's simpl May 9, 2019 · I am working on a caesar cipher program as my final project in java I. For example, if the shift is 3, then the letter A would be replaced by D, B Nov 30, 2009 · 1. // s = 'SERR PBQR PNZC' and k = 13 will produce 'FREE CODE CAMP'. This is the simplest of all, where every character of the message is replaced by its next 3rd character. A Cipher is a method that is used for message encryption for various Jan 29, 2014 · I'm trying to make a simple Caesar cipher in java that accepts 2 arguments. The Caesar cipher is a kind of replacement (substitution Mar 18, 2019 · You can do so with a number of methods, one such is Files. Plain text: Hello. It is a type of substitution cipher in which each letter in the plaintext is 'shifted' a certain number of places down the alphabet. encrypt(myIpValue); And for data decryption: StandardPBEStringEncryptor encryptor = new StandardPBEStringEncryptor(); encryptor. The first known military use of codes was by Julius Caesar in 50 - 60 B. *; /* * @author Nick Carlson */ public class CaesarCipher { //main driver of the program public static void main (String [] args) { getInputAndRunCaesar Mar 23, 2023 · The Caesar cipher is a simple encryption technique that was used by Julius Caesar to send secret messages to his allies. StringTokenizer st = new StringTokenizer ("my name is ceasar"," ", false); while ( st. By Ephraim Description. public static void main (String[] args ){. For this reason, the shift cipher technique is called the Caesar cipher. Jul 8, 2020 · Berikut ini contoh implementasi Caesar Cipher menggunakan pemrograman C++. We can hack the cipher text in various ways. x denotes the value of the letter. If any case (Dn) value becomes negative (-ve), in this case, we will add 26 in the negative value. Dn depicts decryption. lineSeparator())); As for writing to a file, take a look at the PrintStream(File) constructor. length ()-1)) ->. At the end of the assignment, you will have a program that can encrypt, decrypt, and crack the Caesar cipher! Each letter is enciphered with the function (ax+b)mod (26), where b is the magnitude of the shift. Examples: Caesar cipher. The questions says to "Develop a method that accepts as input a shift value and a message. charAt (ind+1); 3. The default shift value of 13 corresponds to the ROT13 cipher. `. Caesar-Cipher. println (st. In Java, if the first argument to the % operator is negative, then the answer will be negative (or 0). This is the common method I've seen for the classic Ceasar "play" cipher: // introduce a local variable, you don't want to perform charAt twice. Where, En depicts encryption. Mar 24, 2015 · String encrypted= encryptor. To encrypt a message, each block of n letters (considered as an n-component vector) is multiplied by an Program Ceaser Ciper in JAVA for Encryption. Scanner; This is a C++ Program to implement Caesar Cipher Encryption algorithm. It is not a very secure * encyption technique, as the frequency of letters present in the English To decrypt the data using the Hill Cipher, first we need to find the inverse of our key matrix. For example, with a shift of 1, A would be replaced by B, B would become C, and so on. The Java program is successfully compiled and run on a Windows system. If a letter is shifted off the end of the alphabet (‘z’), then it is shifted all the way back around to the beginning of the alphabet (‘a’). • Type in either plaintext or ciphertext and print out the result after encryption or decryption (Scanner class). This technique is not so hard and doesn't require much effort. Each letter must be shifted forward n steps in the alphabet. Breach in Caesar Cipher Algorithm. How to do with both upper and lower case input. Caesar Cipher is an encryption algorithm in which each alphabet present in plain text is replaced by alphabet some fixed number of positions down to it. XOR Encryption is an encryption method used to encrypt data and is hard to crack by brute-force method, i. Sender side: Clear text : G E E K. See full list on baeldung. So, let’s look at the steps necessary to take in order to code this. The specific goals are: To write and use functions, and understand the use of helper functions use and manipulate arrays. NoSuchElementException. In cryptography there are many algorithms that are used to achieve the same, but Caesar cipher is the earliest and easiest algorithm used among encryption techniques. java. That's why you are not asking for handouts on the completion of this project by any means. History. next(), run each character through the Caesar cipher but don't store the result anywhere, then read another word with output. It derives its name from the way in which it is encoded. Step 3: Identify that characters location + the key in the The Caesar cipher method is based on a mono-alphabetic cipher and is also called a shift cipher or additive cipher. Breaking-the-Caesar-Cipher Assignment at "Java Programming: Arrays, Lists, and Structured Data" course by Duke University - Coursera Please read the project description pdf uploaded. The encryption process involves selecting a key, which is an integer value representing the number of positions each letter will be shifted. Decryption is converting an encrypted message to its original form. 22 KB. Use comments. Jan 11, 2021 · Implementation. It can also take in an encrypted text and decrypt it. It is based on a keyword's letters. The Caesar cipher, also known as a shift cipher, is one of the simplest forms of encryption. Here is source code of the C++ Program to Implement Caesar Cypher. Encryption is a process of encoding a message using an encryption algorithm. This Java program is to demonstrate Multiplicative Cipher. setandstring; import java. In the java. It works until I get to 23 shifts , then it starts using non-letter symbols for some reason, and I'm not sure why this is happening. Playing around with Vigenere and Caesar cipher - Java command line encryption program. To fix this, I would use only nextLine () and parse the c integer from string (or use string comparsion in the if statements). When encrypting or decrypting, the case is preserved, and non-letters are unchanged. The program output is also shown below. Base64 is used most often for cipher text because it takes up less space than hex, hex is most commonly used for message digests. That file will be read in the train method. Each letter of plain text is replaced by a letter with some fixed number of positions down with alphabet. Cipher text: N L L R. The next step is to find a number which gives the answer 1 Sep 11, 2023 · XOR Cipher. One of the simplest examples of a substitution Caesar Cipher is a simple and old method used to encryption and decryption in computer network. I personally prefer the caesar cipher, since you can assign random shift parameters. Enter the key you would like to use to encrypt (integer): 3. Below is a simple implementation in C++. For decryption just follow the reverse of the encryption process. If the letter is greater than ‘z’ then subtract the letter by 26 or else if the letter is lesser than ‘a’ then add 48 lines (46 loc) · 1. decrypt(encrypted); Or you could just encode or decode your string to base64 example is show here: Base64 Java encode and decode a string. Setup/Installation requirements This JavaScript program encrypts and decrypts messages using the Caesar cipher. Learn about String manipulation and ASCII encoding. InsyaAllah di artikel lain, saya tunjukkan implementasi Caesar Cipher menggunakan pemrograman java berdasarkan 256 karakter ASCII. Using two keys, where key1 is used to encrypt every other character with the Caesar Cipher algorithm, starting with the first character, and key2 is used to encrypt every other character, starting with the second character. Here is my code so far: Dec 22, 2023 · The rail fence cipher (also called a zigzag cipher) is a form of transposition cipher. Jan 11, 2023 · The key used by both sender and receiver is the same in the case of symmetric encryption and decryption. Let's understand the following Oct 21, 2023 · What is Caesar’s Cipher? Caesar Cipher is the simplest method of encoding messages. n denotes the shift or key-value. It will encrypt the test string. in this case, you add the char value of alphabet. I have a method for the encryption that handles lower and uppercase characters. This is a java program that takes in a text, encrypts it and then returns the encrypted text. I'm very new to Java, and I'm still trying to understand the basics. Algorithm. util. Create a Java class named "CaesarCipherExample. Try to run your program and for the first question, enter "1 test". indexOf(c); // if charPositions is -1 then it is not found. Java Caesar Cipher. To do this first find the determinant of our key matrix. The following discussion assumes an elementary knowledge of matrices. For the Vignere cipher, I'd use a Map<Character, Cipher> and a formula that again uses % to CAESAR CIPHER This is a project that uses the caesar cipher method to encrypt and decrypt texts. setPassword(seed); String decrypted = encryptor. In plain terms, this means that the encryption of a letter x is equal to a shift of x *n, where n is the number of letters shifted. The nextLine () reads the rest of the previous line with the integer. A Java application that implements a caesar cipher which is a type of substitution in which each letter is shifted a certain number of places also known as a key, down the alphabet(A-Z). xml file looks like this. Let’s understand by taking a simple plain text and converting it to cipher text. This algorithm is easy to understand and implement. For example, when K = 3 K = 3, ZOOM is encoded as FXAB: The challenge is to write a decoder. Julius Caesar used the shift cipher (additive cipher) technique to communicate with his officers. Here is the source code of the Java Program to Implement Affine Cipher. If you use the % operator as a number of people have hinted at, encoding can be done with one (1) line of code. Step 4: Working with utility. It is a substitution cipher where each letter in the original message (called the plaintext) is replaced with a letter corresponding to a certain number of letters up or down in the alphabet. fromCharCode (13 + temp)'. String str = ""; Feb 4, 2020 · I am new in JAVA Programming and I am trying to create a caesar cipher encrypt/decrypt program. In cryptography, a Caesar cipher, also known as Caesar's You create a Cipher instance by calling its getInstance () method with a parameter telling what type of encryption algorithm you want to use. The action of a Caesar cipher is to replace each plaintext letter with a different one a fixed number of places down the alphabet. Jun 23, 2015 · 1. It works by shifting the letters in the plaintext message by a certain number of positions, known as the "shift" or "key". Just wanting a bit of guidance. The Multiplicative Cipher can be expressed in a more mathematical form as follows: E n (x) = (x*n) mod 26. In our case determinant evaluates to 37, which is again greater than 26 so we will find mod26 of out determinant i. This line. Jan 20, 2020 · The Caesar cipher is one of the earliest known and simplest ciphers. Given plain text, the task is to implement the Monoalphabetic Cipher. A cipher obscures text. 4. This program uses the Caesar cipher to encrypt and decrypt messages. Jul 3, 2023 · Even in 40 BC, messages were being intercepted. the char you entered is not z (ind < (alphabet. Invented by Lester S. getInstance( "AES" ); This example creates a Cipher instance using the encryption algorithm called AES. IMPLEMENTATION OF THE CAESAR CIPHER METHOD Three programs based on Java, C++, and Python languages have been developed to implement the Caesar cipher method using the user-defined key for the shift. collect(Collectors. each letter with a number corresponding to the position of the letter in the alphabet May 8, 2014 · One file has to be long with a bunch of words in it at least 1000. This encryption technique is used to substitute the actual messages with a fixed number of shifts to make them encrypted. The Caesar cipher specified that each letter in the alphabet would be Programming Exercise: Breaking the Caesar Cipher Before attempting these assignments, you should type in, compile, and understand the example programs from the lesson, including: 1) counting the twenty most common words from Shakespeare’s plays, 2) counting the resulting random rolls of dice (how many 2’s, 3’s, 4’s, etc), and 3 Secondly, your read/write logic is all wrong. Oct 26, 2015 · The program has to just encrypt the input word for the input key and not decrypt. Enkripsi merupakan salah satu teknik keamanan yang paling sering digunakan. Let’s assume that the key used here is 7. int letter= (letterCiphered+key2); The vigenere cipher is an algorithm of encrypting an alphabetic text that uses a series of interwoven caesar ciphers. java file. Caesar Cipher with a key of 3, the encryption would Apr 28, 2018 · Output with message "apple" and a cipher shift of 3: Enter '0' to type a phrase or enter '1' to specify the path to a text document: 0. One being the phrase, and the next being the shift of the letters. Here is the source code of the Java Program to Enode a Message Using Playfair Cipher. It is a one to one mapping. Examples of monoalphabetic ciphers would include the Caesar-shift cipher, where each letter is shifted based on a numeric key, and the atbash cipher, where each letter is mapped Mar 23, 2021 · This video explains the Caesar Cipher (cryptosystem) and walks through the process of implementing it in Java. May 15, 2015 · So, I'm trying to come up with a way to do an encryption/decryption of a caesar cipher (where you take in a value, then shift the letters that many times along the alphabet, for example, if the key was 3, then a would become d, b would be e, and c would be f and so on) but I need to use recursion, rather than iteration. It is a simple form of polyalphabetic substitution. com Apr 7, 2024 · Here you will get program for caesar cipher in Java for encryption and decryption. Today we are presenting you one of the most po Jul 21, 2021 · Hill cipher is a polygraphic substitution cipher based on linear algebra. One of the ways is Brute Force Technique, which involves trying every possible decryption key. charAt(i); int charPosition = ALPHABET. Pages are continually updated to stay current, with code correctness a top priority. Usually cipher text is base64 encoded, base16 (hex) also works well. Step 1 (Mapping Plaintext) : Step 2 (Encrypting and Obtaining CipherText) : Step 3 (Decrypting and Obtaining our original Text) : In this post, we will see about Caesar Cipher in Java. io. here is a sample of how to encypt using the ceasar cipher but i did the the. The Caesar Cipher is a simple substitution cipher that replaces each letter in the plaintext with a letter a fixed number of positions down the alphabet. Contribute to arifsuz/Program-Caesar-Cipher-JAVA development by creating an account on GitHub. Stream that, and collect it with line separators. Like, . Often the simple scheme A = 0, B = 1, …, Z = 25 is used, but this is not an essential feature of the cipher. Question: 12. This project showcases the implementation of the Caesar Cipher algorithm using object-oriented programming (OOP) concepts and the strategy design pattern. Mar 27, 2024 · The formula of decryption is: Dn(x) = (x - n) mod 26. offset = offset % 26 + 26; covers the possible case that the offset passed in was negative. The algorithm is simple; for example, if we perform encryption on the text delftstack, the Caesar Cipher Dec 28, 2023 · Solution 2: ## Caesar Cipher in Java. In this cipher, each letter of the alphabet is shifted by a certain number of places. May 27, 2016 · I have problem in Caeser cipher, my program works well for Lower case input. Receiver side: Caesar Cipher Technique is the simple and easy method of encryption technique. For instance, if we were to encrypt the plain text "abc" by an offset of 3, the resulting cipher text would be "def". Here's an example of how I wrote it: // s = string to encrypt, k = shift value. The following diagram depicts the working of Caesar cipher algorithm implementation −. Program Explanation: 1. Enter message that you would like to have encrypted. Dec 19, 2018 · To implement this code, at least in JAVA, you would need to think through what is actually being done. hasMoreTokens () ) System. IOException; import java. To become acquainted with cryptography. We reverse this by shifting each letter back. CaesarCipher. All the logic to encrypt and decrypt our message will be written in this class. Do not enter numerical values: apple. The C++ program is successfully compiled and run on a Linux system. /** * Methods to encrypt and decript Strings using a Caesar Cipher. You need a file with an encrypted message and another file for the program to write the decrypted message. Here is an encrypted message first using 3 positions of the Caesar Cipher and then 5 positions. Nov 25, 2022 · After implementing the above code, the design of the activity_main. Step 2: Find that character’s location within the alphabet. //package line only needed by netbeans //package caesarcipher; import java. In a transposition cipher, the order of the alphabets is re-arranged to obtain the cipher-text. 184 lines (150 loc) · 7. Here is an example of creating a Java Cipher instance: Cipher cipher = Cipher. My professor told me I shouldn't use any. Dot Net Perls is a collection of tested code examples. 5. Feb 6, 2018 · Caesar Cipher is applied individually to each letter in the string. The Shift Cypher is another name for it. Base64 library you will find byteArrayToBase64 () and base64ToByteArray (). Algorithm Assignment. Nov 18, 2016 · I am trying to write a java program that encode a plain text using caesar cipher. package com. There is code available online but all are using for loops. txt. It offers users a menu to select between encryption or decryption and requests text input. Use the Caesar cipher algorithm to transform text. This algorithm was first described in 1553 by Giovan Battista Bellaso. In the Caesar cipher, letters are shifted by a specified number of places in the alphabet. README. In cryptography, we used to study different algorithms or techniques to encrypt and decrypt a different sets of messages to gain confidentiality Oct 12, 2023 · This tutorial demonstrates how to perform encryption and decryption using Caesar Cipher in Java. Following user input, the program utilizes the Caesar cipher, shifting each alphabet letter by three positions. This program has two forms of encryption: Using one key, where it shifts the alphabet by that key number. For the Caesar cipher, you only need a single for-loop that iterates over the characters in the plaintext string and encodes each one in turn. /. 18th February, 2022. int letterCiphered= (letter-key2); To decipher such a message you should shift each character of the cipher by the same value but in the other direction. e. 2. Last Updated : 11 Aug, 2021. See examples, advantages, disadvantages, and a Java program implementation. I don't know whats the problem but i get the error: Exception in thread "main" java. The Vigenère cipher is a method of encrypting alphabetic text by using a series of different Caesar ciphers based on the letters of a keyword. Playfair Cipher Program in Java with java tutorial, features, history, variables, object, programs, operators, oops concept, array, string, map, math, methods Nov 22, 2018 · Caesar Cipher using Frequency Analysis** in Java: this is my code for the decode part: May 10, 2014 · I am new in Java and I need to write an algorithm for cracking Caesar's cipher using brute force and then matching the words from the dictionary to find the correct shift. It is simple type of substitution cipher. It is a type of substitution cipher in which each letter in the plaintext is shifted a certain number of places down the alphabet. Jan 20, 2016 · Enkripsi Caesar Cipher dengan Java. if so, you add that exact char to the encoded value, since you don't have another to encode it with. . Assignment 2: Caesar Cipher. 3. At the bottom you'll find the uncompleted java code • Choose between encryption and decryption (if-else statement). The Caesar cipher is a simple substitution cipher that is named after Julius Caesar, who is said to have used it to communicate with his generals. Java implementation of the Caesar cipher. Dec 10, 2021 · The Caesar cipher is a technique in which an encryption algorithm is used to change some text for gaining integrity, confidentiality, or security of a message. char c = plainText. sanfoundry. Step 1: Identify the character within the sentence. It is an example of a polyalphabetic substitution cipher. print(" " + data. The method is named after Julius Caesar, who apparently To use the Caesar Cipher program in Java, follow these steps: Create a new Java project in your preferred Integrated Development Environment (IDE). A Caesar Cipher * is an encryption method that operates by shifting letters of your message a * certain number of characters forwards or backwards. Code. I have the program set up with the DecodeChar method to decode the provided file, which is juust a wall of jumbled text from the Hitchhiker's Guide to the Galaxy in Caesar Cipher. Nov 3, 2019 · I'm just a starter at java, and I'm trying to figure out the codingbat "Ceaser Cipher" problem. C. , 37 = 11 mod 26. For example:-. Oct 15, 2022 · The assignment was to create a Caesar Cipher encoder in Java. here is my code: public class CeaserCipher { public @TechRanch Welcome to Tech-Ranch! A place where we learn and earn technical skills in the most efficient way. At this moment I get simple encryption result however I want to use following pattern as the encryption of the text in the file. Caesar Cipher in Java. joining(System. " Implement the encrypt () method to encrypt the plaintext using the Caesar Cipher algorithm. In classical cryptography, the Hill cipher is a polygraphic substitution cipher based on linear algebra. We have defined few specific set of position that generated a cipher text. prefs. The idea behind the Caesar Cipher is to replace each character in any given input by a fixed number of positions from their location within the alphabet. The shift value will be no less than -25 and no greater than 25. nextToken ()); in the above 3 lines this should tell all on how to use the string tokenizer. Below I have shared a program to implement caesar cipher in C and C++. The Playfair cipher or Playfair square is a manual symmetric encryption technique and was the first literal digraph substitution cipher. Sam Allen is passionate about computer languages. 22 Substitution Cipher* You will be writing a simple Java program that implements an ancient form of encryption known as a substitution cipher or a Caesar cip (after Julius Caesar who reportedly used it to send messages to his armies) or a shift cipher in a Caesar cipher, the letters in a message are replaced by the letters of a "shifted" alphabet. out. next()); and write that second word to the output completely un-encoded, completely discarding the first word. Monoalphabetic Cipher is a cipher where the letters of the plain text are mapped to ciphertext letters based on a single alphabetic key. Yudi Setiawan • 20 Januari 2016. Banyak data yang bisa di enkrip misal, isi pesan, citra digital (gambar), password penting dan lain sebagainya. Resources Caesar Cipher. Like A will be replaced by D, C will be replaced by F, and so on. I cannot see where did I go wrong I tried reviewing my code for several times but I cant seem to find out the problem. help me to solve this problem. The Caesar cipher is a ridiculously weak cipher and Oct 12, 2023 · Caesar Cipher は、暗号化を実行するための最も簡単な方法の 1つです。このチュートリアルでは、Java で CaesarCipher を使用して暗号化と復号化を実行する方法を示します。 Java のシーザー暗号. Caesar Cipher is of the earliest approaches for performing encryption; it can be implemented in any programming language. You read a word with data. If it's negative, then offset % 26 makes the result between -25 and 0, so that adding 26 will make it positive (it's just important that May 29, 2017 · Also, when you build the string, it should just be 'String. Each program starts by asking the user for the source file, the target file, and the key. e generating random encryption keys to match with the correct one. The full code that I have so far, is as follows: This is a java program to implement hill cipher. This algorithm was named after Julius Caesar who was a Roman general Sep 7, 2022 · Caesar cipher is an encryption method that shifts the letters of a message by a constant offset for producing an encrypted message. Step-2: Then if the letter is greater than ‘a’ and lesser than ‘z’ then add the letter to the shift again. Write these methods in a CaesarCipher class you can use in the next lesson. The program implementation of Oct 30, 2011 · 0. Each letter is represented by a number modulo 26. You will start with the Caesar Cipher algorithm you learned about in the videos, and you will make some enhancements to it, so that it works with all letters (both uppercase and lowercase) and to make it a little bit harder to decrypt. Caesar cipher. Create a new java class as shown below and name it as “ utility “. Jan 29, 2015 · The encoding algorithm is a Caesar cipher with a shift ( S S) that depends on a parameter ( K K) and its position in the word ( P P, where P = 1 P = 1 for the first letter of each word): S = 3 S = 3, P + K P + K. Here is the source code of the Java Program to Implement the Vigenere Cypher. Caesar Cipher は、暗号化を実行するための最も初期のアプローチです。 Feb 17, 2015 · This is Caesar cipher program, In this Program Decryption process works completely but encryption process have problem. Hill in 1929, it was the first polygraphic cipher in which it was practical (though barely) to operate on more than three symbols at once. I have a file which contains the plain text and another one where the encoded text should be put. Example. readAllLines(Path), which returns a List<String> of the file lines. The shift value must be an integer between 0 and 25, inclusive. In the rail fence cipher, the plain-text is written downwards and diagonally on successive rails of an LAB MANUAL caesar cipher program import public class caesarcipher public static final string alphabet public static string encrypt(string plaintext, int Java library for Ceasar Cipher (Keyed Caesar) that can: Encrypt & decrypt english text using keyword and keyword offset (shift) Hack encrypted english text using frequency of letters and dictionary of words Oct 21, 2013 · Oct 21, 2013 at 8:50. zip. Java Program on Multiplicative Cipher. I'm creating a program to do a Caesar Cipher, which shifts the letters in a word one time when I hit enter, and prompts the user to shift again or quit. Java Program on Caesar Cipher. The Caesar cipher, unlike modern systems, is easy to break—given the right knowledge. Unfortunately, my program is only working in lower cases. Thanks in advance. Mar 7, 2023 · 1. The concept of implementation is to first define XOR – encryption key and then to perform XOR operation of the Aug 11, 2021 · Java Program to Implement the Monoalphabetic Cypher. As a requirement, the cipher should keep capital letters capital, and lower case letters lower case. Caesar Cipher Introduction § The Caesar cipher is one of the earliest known and simplest ciphers. However I have hit a wall trying to adjust the algorithm to work the shift factor in the opposite direction to decrypt text already run through the program. Dec 16, 2017 · In that case you do the same thing: add it and continue. Jan 21, 2009 · lets say for example. The cipher illustrated here uses a left shift of 3, so that (for example) each occurrence of E in the plaintext becomes B in the ciphertext. -----Part 1: The Caesar Cipher----- The use of codes (or ciphers) as a means of hiding the meaning of messages traces its roots to ancient history. It includes encoding and decoding. May 4, 2016 · I have created simple encryption program to encrypt any input file and save it in new output file. May 11, 2023 · Learn how to encrypt and decrypt messages using the Caesar cipher, a simple substitution cipher with a fixed key. charAt (0) Java-Cryptography-Program. It seems that your encryption just shifts every character of the message by a given value. wp ug hu ft yt cl jw zq ft sa