Ultra Encryption Standard (UES) Version-II: Symmetric key Cryptosystem using generalized modified Vernam Cipher method, Permutation method, Columnar Transposition method and TTJSA method. A. Satyaki Roy 1, B. Navajit Maitra 2, C. Joyshree Nath 3, D. Shalabh Agarwal 4 and E. Asoke Nath 5 Department of Computer Science, St. Xavier’s College (Autonomous), Kolkata, India 1, 2, 4, 5 A.K.Chaudhuri School of IT, Raja Bazar Science College, Calcutta University, Kolkata, India 3 Abstract- Nath et al recently developed encryption method available to decode password of some unknown e-mail. called UES version-I where they have 3 distinct encryption Under no circumstances the confidential data should be methods such as Modified generalized Vernam Cipher intercepted by any intruder while transmitting from client method using feedback, multiple round transposition machine to server or to another client machine. Due this method and permutation method have been amalgamated. intrusion problem now the network security and A new combined cryptographic method called UES cryptography is an emerging research area where the people Version-II has been introduced here as the extension of are trying to develop some good encryption algorithm so UES version-I. Nath et al. have already developed several that no intruder can intercept the encrypted message. Nath et al. had developed some advanced symmetric key symmetric key methods such as MSA, DJSA, NJJSAA, algorithm [1-8]. In the present work we are proposing a TTJSA, TTSJA, DJMNA, DJJSA, UES-I etc. In the present symmetric key method called UES version-II which is a work multiple methods such as generalized modified combination of 4 distinct cryptographic methods, namely, vernam Cipher method Permutation method, Columnar (i) Generalized Modified Vernam Cipher Method, (ii) transposition method and TTJSA have been implemented. Permutation method (iii)Columnar transposition method UES-I has been extended to UES-II by adding one and (iv) TTJSA modules. We have tested this method on encryption module called TTJSA to make the encryption various types of known text files and we have found that, standard harder than UES-I. An encryption key pad in even if there is repetition in the input file, the encrypted file Vernam Cipher Method and also the feedback used in this contains no repetition of patterns. The real challenge in the method is considered to make the encryption process UES version-II algorithm was to ensure the effective stronger. UES-II incorporates multiple encryption and integration of the four levels of encryption to produce decryption to defeat common cryptography attack such as strong encryption with the features such a multiple differential attack or simple plain text attack. encryption, randomized key generation and a new method Keywords: encryption, decryption, feedback, cycling, i.e. TTJSA. randomized Vernam key, TTJSA. II. UES VERSION -II ALGORITHM I. INTRODUCTION ENCRYPTION PROCESS In the current communication network it is a real challenge us to send confidential data/information from one computer In UES-II we have four distinct levels of encryption such to another computer. When a sender is sending some as Modified Vernam Cipher with feedback, Columnar confidential data, there may be a middle man attack and the data may be intercepted and diverted to different places. Transposition, Randomization Encryption Process and The confidentiality and security of data has now become a finally TTJSA[ref-no]. The first three levels of encryption big challenge in data communication network. Due to are performed in blocks of 900 bytes. The residual bytes (of network facility the access of data is now very easy and the size less than 900 bytes) are encrypted with the Modified hackers are always try to hack data from the network. The Vernam Cipher Encryption Method. The output is trainers and the teachers must be careful to send question papers or marks sheet through e-mail as there is no encrypted further by TTJSA method. TTJSA method guarantee that it will not be intercepted by someone. In comprises of 3 distinct encryption methods namely (i) MSA banking and corporate sectors the finance or management method[Ref-no], (ii) NJJSAA methd [Ref-no], data must be secured if by chance the data goes to the (iii)Generalized modified vernam cipher method with hacker then the entire service will be collapsed. Password feedback. The randomized vernam key is generated in breaking is now not a problem. Many public software are every iteration from a mathematical calculation from the will now undergo randomization/permutation encryption user given password which can be 64-byte long. While method. doing columnar transposition method the sequence of the Step 22: The output file from the randomization process holds the encrypted 900 bytes. column extraction is also decided internally from the Step 23: The 900 bytes is written to the cipher file name password entered by the user. The password will also provided by the user. decide the number of times encryption is to be performed. Step 24: The value of ‘count’ is incremented by 1. Goto 17. Integration and key generation algorithm Step 25: Once the control breaks from the loop, the Step 1: Start program is left to process the residual bytes from the input Step 2: Input the plain text file name in 'plain[]' (The plain file. file may be of any format). Step 26: The residual bytes are processed by the modified Step 3: Input the cipher text file name in 'cipher[]' vernam cipher encryption technique. The encrypted bits are Step4: The extracts the first byte in the file and stores it in again written into the cipher file which serves as the input 'ch' and it extracts the last byte of the file and stores in 'cha'. for the next iterations of encryption. It replaces the first byte of the file with character with Step 27: Increment p ASCII (ch+cha)%256. Step 28: Goto step-12 Step 5: The user enters a 64 byte encryption-key that is Step 29: When the control reaches this encryption the stored in 'key[]'. Modified Vernam Cipher, Columnar Transposition, and Step 6: Now the algorithm computes the 'cod' value equal Randomization modules are complete. The file is further to Σ key[i]*(i+1) where i represents the position of every fed as input to the TTJSA module. character in the key. Step 30: The output is again written back to the cipher file Step 7: The encryption number (enc) is computed by whose name is provided by the user. calculating the cod modulus 17. If enc <0 then enc=7 Step 31: End Step 8: Take the input file pointer to the end of the input Algorithm for the first level of encryption – file, such that the size of the input file can be computed. (The size of the input file is stored in long integer variable modified vernam cipher encryption method 'n'.) with feedback. Step 1: Start Step 9: Declare a variable 'n1' of long int datatype where Step 2: The plain text serves as the input file for the n1 will store the number of iterations. Each iteration will program. process a 30 X 30 bytes block in every iteration of Step 3: Create a dictionary of characters in the character encryption. array where position i will be the ASCII value for the Step 10: Introduce a variable p=0. character placed in the i-th location of the array. Step 11: Compute cod=cod modulus 256 Step 4: Define the encryption key which must be same as Step 12: If p is greater than or equal to enc then GOTO the key provided during decryption. step 29. Step 5: Start processing the characters in the input file. Step 13: Increment cod and perform cod=cod%256; Define a integer variable ‘feed’ and initialize it with 0. Step 14: Now create a key file by printing the characters Step 6: Extract a character in the input file and store in ch1. with ASCII values of 0-255 in rotation. The first character If ch1is NULL, goto 12 is however the character with ASCII ‘cod’. This key file Step 7: Extract a single character from the key file. serves as the input for the Modified Vernam Cipher with Step 8: Compute m,n from the arrays arr[] where m and n feedback. are the ASCII values for the first characters of the input file Step 15: This key is further randomized using and key files. randomization module and stored in the file ‘file1.c’. Step 9: Perform addition m=m+n+feed. Then calculate Step 16: Initialize integer variable count to 0. n=m modulus 256.The value of n is called the ‘Feedback’ Step 17: If count greater than or equal to n1 then Goto 25 which allows the program to encrypt the characters in the Step 18: Define the intermediate file which will open, plain file. extract and process the first 900 bytes of the plain file. Step 19: The 900 bytes that have been extracted now is encrypted with the Modified Vernam Encryption process with Feedback Step 20: The output from the modified vernam cipher encryption process is fed as input to the columnar transposition encryption process. Step 21: The output from the columnar encryption method Table 1: Modified Vernam Cipher Step 10: If col is equal to n then increment row by 1 and Key: abc intialize col variable to 0 to keep a check on the row and aaa ┬àI column parameters. Step 11: Goto 9 until the storing of the intermediate plain text in the array is complete. Plain text: A A A Step 12. If col==0 then we decrement the row index by 1 to ensure that the character array arr[] does not produce an Plain Index(m): 97 97 97 extra row.This happens when a character is placed at the last column of a particular row.