How can I decrypt a string and get the algorithm used for the encryption

Question

I want to know how to decrypt a text without knowing the key used or the algorithm such as this text:

RUE2RDRDMDE5OTpxci1hZG1pbi1yZWFkZXIxOjAwMDdDMUJBOEU4Q0IyOUQwNjg1RkJDRkMzMDdDMjc4:Nzg0MTk5MDUzMjA1OTEyXzk3MTUwODkzODk1MjpuY2hjNnkzenFkb2tvZXR0cWR2OTo2OEJFNkFCMTY4RjNGMTdFNUJFRjY3OTgwQjgwMDBTRVZBQURZRUVSVUFBTDBBTUtGdFM2QVNIQUwwRUE=

does this text has any signs that could help me to know at least what is the algorithm used? and then how to decrypt without knowing the key?

Answer 1

This is base64 encrypted there are no key needed for this. But in general, you can test all possible encryption algorithms and look at all the results.

Decoded: EA6D4C0199:qr-admin-reader1:0007C1BA8E8CB29D0685FBCFC307C278784199053205912_971508938952:nchc6y3zqdokoettqdv9:68BE6AB168F3F17E5BEF67980B8000SEVAADYEERUAAL0AMKFtS6ASHAL0EA