I have intercepted some data for which i don't know which algorithm has been used to encrypt this data, this data has been for sure encrypted before transmitting, to decrypt the data i should certainly must find the algorithm being used as well key if required.
Example of data;
6E190A5AA10FCB1558433669884F9B07040EFC06 > 20 bytes encrypted
156785AF544E7D33C14B8F7AA5EBC714D97065C80122BB15BB522A2F18AA60303DAF1303A38CBAA9D0EB829720CD131699 > 49 bytes encrypted
If I use common algorithm 3DES/AES/RSA, then block size of data is not enough to fulfill the condition for these common algorithms, because these common algorithm requires data to be at least 16 bytes or multiple of 16 bytes. Except RSA, which, I am not sure but, in RSA case 20 bytes data encrypt and decrypt will also require a 20 bytes RSA key, which makes no sense.
I study hash algorithms keyless but its one way encrypt so its not possible, possibility is keyed algorithm has been used to encrypt and decrypt the data on both side, it is also possible that if data encrypted 2 times/rounds using same algo the size becomes 49, most of time it appears 20 bytes blocks.
More ever the data comes random in consecutive pockets which also proves the if common algorithm in use then CBC mode has been used to randomize the repeated plain text encrypted packets, (the plain text transmission often repeats)
I will repeat my question: which algorithm can possibly encrypt and decrypt data of block size 20 bytes and 49 bytes, or may be any size?